diff --git a/libs/arpa_inet.go b/libs/arpa_inet.go
index da9ed6e..a7155f8 100644
--- a/libs/arpa_inet.go
+++ b/libs/arpa_inet.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/runtime/cnet"
 	"github.com/gotranspile/cxgo/types"
 )
@@ -13,9 +11,6 @@ const (
 	arpaInetH = "arpa/inet.h"
 )
 
-//go:embed includes/arpa_inet.h
-var harpaInet string
-
 func init() {
 	RegisterLibrary(arpaInetH, func(c *Env) *Library {
 		inAddrT := types.NamedTGo("in_addr_t", "cnet.Addr", types.UintT(8))
@@ -45,7 +40,6 @@ func init() {
 				"inet_ntop": c.NewIdent("inet_ntop", "cnet.Ntop", cnet.Ntop, c.FuncTT(strT, types.IntT(4), c.PtrT(nil), strT, sockLenT)),
 				"inet_pton": c.NewIdent("inet_pton", "cnet.Pton", cnet.Pton, c.FuncTT(strT, types.IntT(4), strT, c.PtrT(nil))),
 			},
-			Header: harpaInet,
 		}
 	})
 }
diff --git a/libs/ctype.go b/libs/ctype.go
index 8187f52..71f7f79 100644
--- a/libs/ctype.go
+++ b/libs/ctype.go
@@ -39,24 +39,6 @@ func init() {
 				"tolower": c.NewIdent("tolower", "unicode.ToLower", unicode.ToLower, toT),
 				"toupper": c.NewIdent("toupper", "unicode.ToUpper", unicode.ToUpper, toT),
 			},
-			// TODO
-			Header: `
-_cxgo_go_bool isalnum(_cxgo_go_rune);
-_cxgo_go_bool isalpha(_cxgo_go_rune);
-_cxgo_go_bool isascii(_cxgo_go_rune);
-_cxgo_go_bool iscntrl(_cxgo_go_rune);
-_cxgo_go_bool isdigit(_cxgo_go_rune);
-_cxgo_go_bool isgraph(_cxgo_go_rune);
-_cxgo_go_bool islower(_cxgo_go_rune);
-_cxgo_go_bool isprint(_cxgo_go_rune);
-_cxgo_go_bool ispunct(_cxgo_go_rune);
-_cxgo_go_bool isspace(_cxgo_go_rune);
-_cxgo_go_bool isupper(_cxgo_go_rune);
-_cxgo_go_bool isxdigit(_cxgo_go_rune);
-_cxgo_go_rune toascii(_cxgo_go_rune);
-_cxgo_go_rune tolower(_cxgo_go_rune);
-_cxgo_go_rune toupper(_cxgo_go_rune);
-`,
 		}
 	})
 }
diff --git a/libs/dlfcn.go b/libs/dlfcn.go
index 94b45f5..8681456 100644
--- a/libs/dlfcn.go
+++ b/libs/dlfcn.go
@@ -31,8 +31,6 @@ func init() {
 				"dlopen": RuntimePrefix + "dlopen",
 			},
 			Header: `
-#include <` + BuiltinH + `>
-
 const int RTLD_LAZY = 1;
 const int RTLD_NOW = 2;
 const int RTLD_GLOBAL = 4;
diff --git a/libs/errno.go b/libs/errno.go
index a2aadf5..0707749 100644
--- a/libs/errno.go
+++ b/libs/errno.go
@@ -22,11 +22,8 @@ func init() {
 	})
 }
 
-
 func errnoHeader() string {
-
 	lines := []string{
-		"#include <" + BuiltinH + ">",
 		"_cxgo_go_int errno = 0;",
 		"char* strerror (_cxgo_go_int errnum);",
 	}
diff --git a/libs/fenv.go b/libs/fenv.go
index bf4cb2e..0e2847d 100644
--- a/libs/fenv.go
+++ b/libs/fenv.go
@@ -21,12 +21,6 @@ func init() {
 				"FE_TOWARDZERO": c.NewIdent("FE_TOWARDZERO", "cmath.TowardZero", cmath.TowardZero, gint),
 				"fesetround":    c.NewIdent("fesetround", "cmath.FSetRound", cmath.FSetRound, c.FuncTT(intT, intT)),
 			},
-			// TODO
-			Header: `
-#include <` + BuiltinH + `>
-const _cxgo_go_int FE_TOWARDZERO = 1;
-_cxgo_sint32 fesetround(_cxgo_sint32 round);
-`,
 		}
 	})
 }
diff --git a/libs/glob.go b/libs/glob.go
index c9c8118..f8aba78 100644
--- a/libs/glob.go
+++ b/libs/glob.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/runtime/stdio"
 	"github.com/gotranspile/cxgo/types"
 )
@@ -11,9 +9,6 @@ const (
 	globH = "glob.h"
 )
 
-//go:embed includes/glob.h
-var hglob string
-
 func init() {
 	RegisterLibrary(globH, func(c *Env) *Library {
 		gint := c.Go().Int()
@@ -38,8 +33,6 @@ func init() {
 			Idents: map[string]*types.Ident{
 				"GLOB_NOESCAPE": c.NewIdent("GLOB_NOESCAPE", "stdio.GlobNoEscape", stdio.GlobNoEscape, gint),
 			},
-			// TODO
-			Header: hglob,
 		}
 	})
 }
diff --git a/libs/includes/embed/AL/al.h b/libs/includes/AL/al.h
similarity index 100%
rename from libs/includes/embed/AL/al.h
rename to libs/includes/AL/al.h
diff --git a/libs/includes/embed/AL/alc.h b/libs/includes/AL/alc.h
similarity index 100%
rename from libs/includes/embed/AL/alc.h
rename to libs/includes/AL/alc.h
diff --git a/libs/includes/embed/GL/gl.h b/libs/includes/GL/gl.h
similarity index 100%
rename from libs/includes/embed/GL/gl.h
rename to libs/includes/GL/gl.h
diff --git a/libs/includes/SDL2/SDL.h b/libs/includes/SDL2/SDL.h
new file mode 100644
index 0000000..68029b9
--- /dev/null
+++ b/libs/includes/SDL2/SDL.h
@@ -0,0 +1,230 @@
+#define Uint32 _cxgo_uint32
+#define Uint16 _cxgo_uint16
+#define Uint8 _cxgo_uint8
+#define Sint32 _cxgo_sint32
+#define Sint16 _cxgo_sint16
+#define Sint8 _cxgo_sint8
+#define SDL_bool _cxgo_go_bool
+typedef Sint32 SDL_FingerID;
+typedef Sint32 SDL_Scancode;
+typedef Sint32 SDL_Keymod;
+typedef Sint32 SDL_BlendMode;
+typedef Sint32 SDL_TimerID;
+
+
+#define SDL_TRUE 1
+#define SDL_FALSE 0
+const Sint32 SDL_PIXELFORMAT_RGBA5551 = 1;
+const Sint32 SDL_PIXELFORMAT_RGB565 = 2;
+const Sint32 SDL_PIXELFORMAT_RGB555 = 3;
+
+const Sint32 SDL_RENDERER_ACCELERATED = 1;
+const Sint32 SDL_RENDERER_PRESENTVSYNC = 2;
+
+#define SDL_NUM_SCANCODES 512
+
+typedef struct{
+  Sint16 x, y;
+  Uint16 w, h;
+} SDL_Rect;
+
+#define SDL_TEXTEDITING 770
+#define SDL_TEXTINPUT 771
+#define SDL_KEYDOWN 768
+#define SDL_KEYUP 769
+#define SDL_MOUSEBUTTONDOWN 1025
+#define SDL_MOUSEBUTTONUP 1026
+#define SDL_MOUSEMOTION 1024
+#define SDL_MOUSEWHEEL 1027
+#define SDL_WINDOWEVENT 512
+
+#define SDL_WINDOWEVENT_FOCUS_LOST 13
+#define SDL_WINDOWEVENT_FOCUS_GAINED 12
+
+#define SDL_BUTTON_LEFT 1
+#define SDL_BUTTON_RIGHT 3
+#define SDL_BUTTON_MIDDLE 2
+
+const Sint32 SDL_PRESSED = 1;
+
+const Sint32 SDL_SCANCODE_SPACE = 1;
+const Sint32 KMOD_LSHIFT = 1;
+const Sint32 KMOD_RSHIFT = 2;
+const Sint32 KMOD_RALT = 3;
+
+const Uint32 SDL_INIT_VIDEO = 1;
+const Uint32 SDL_INIT_TIMER = 2;
+const Sint32 SDL_WINDOWPOS_UNDEFINED = -1;
+const Sint32 SDL_WINDOWPOS_CENTERED = -2;
+const Uint32 SDL_WINDOW_RESIZABLE = 1;
+const Uint32 SDL_WINDOW_OPENGL = 2;
+const SDL_BlendMode SDL_BLENDMODE_NONE = 1;
+
+typedef struct{
+    SDL_Scancode scancode;
+} SDL_Keysym;
+
+typedef struct{
+    SDL_Keysym keysym;
+    Uint8 state;
+} SDL_KeyboardEvent;
+
+typedef struct{
+    Uint8 button;
+    Uint8 state;
+    Sint32 x,y;
+} SDL_MouseButtonEvent;
+
+typedef struct{
+    Sint32 x, y;
+    Sint32 xrel, yrel;
+} SDL_MouseMotionEvent;
+
+typedef struct{
+    Sint32 x, y;
+} SDL_MouseWheelEvent;
+
+typedef struct{} SDL_TouchFingerEvent;
+
+typedef struct{
+    char text[32];
+} SDL_TextEditingEvent;
+
+typedef struct{
+    char text[32];
+} SDL_TextInputEvent;
+
+typedef struct{
+    Uint8 event;
+} SDL_WindowEvent;
+
+typedef struct{
+    int type;
+    SDL_TextEditingEvent edit;
+    SDL_TextInputEvent text;
+    SDL_KeyboardEvent key;
+    SDL_MouseButtonEvent button;
+    SDL_MouseMotionEvent motion;
+    SDL_MouseWheelEvent wheel;
+    SDL_WindowEvent window;
+} SDL_Event;
+
+const Uint32 SDL_WINDOW_FULLSCREEN_DESKTOP = 0;
+
+typedef struct SDL_GLContext {} SDL_GLContext;
+
+typedef struct SDL_Window {
+	Sint32 (*SetFullscreen)(Uint32 flags);
+	void (*GetSize)(Sint32 *w, Sint32 *h);
+	void (*GetPosition)(Sint32 *x, Sint32 *y);
+	void (*SetSize)(Sint32 w, Sint32 h);
+	void (*SetPosition)(Sint32 x, Sint32 y);
+	void (*Minimize)(void);
+	void (*Restore)(void);
+	void (*SetGrab)(SDL_bool);
+	void (*SetResizable)(SDL_bool);
+	void (*SetBordered)(SDL_bool);
+	void (*SetTitle)(const char*);
+	Sint32 (*GetDisplayIndex)(void);
+	void (*GLGetDrawableSize)(Sint32* w, Sint32* h);
+	void (*GLSwapWindow)(void);
+	SDL_GLContext (*GLCreateContext)(void);
+} SDL_Window;
+
+const char* SDL_GetError(void);
+
+Uint32 SDL_GetTicks(void);
+SDL_Window* SDL_CreateWindow(const char* title, Sint32 x, Sint32 y, Sint32 w, Sint32 h, Uint32 flags);
+#define SDL_SetWindowFullscreen(win, flags) ((SDL_Window*)win)->SetFullscreen(flags)
+#define SDL_SetWindowSize(win, w, h) ((SDL_Window*)win)->SetSize(w, h)
+#define SDL_SetWindowPosition(win, x, y) ((SDL_Window*)win)->SetPosition(x, y)
+#define SDL_SetWindowGrab(win, v) ((SDL_Window*)win)->SetGrab(v)
+#define SDL_SetWindowTitle(win, v) ((SDL_Window*)win)->SetTitle(v)
+#define SDL_MinimizeWindow(win) ((SDL_Window*)win)->Minimize()
+#define SDL_RestoreWindow(win) ((SDL_Window*)win)->Restore()
+#define SDL_GetWindowDisplayIndex(win) ((SDL_Window*)win)->GetDisplayIndex()
+#define SDL_SetWindowResizable(win, v) ((SDL_Window*)win)->SetResizable(v)
+#define SDL_SetWindowBordered(win, v) ((SDL_Window*)win)->SetBordered(v)
+#define SDL_GetWindowPosition(win, x, y) ((SDL_Window*)win)->GetPosition(x, y)
+#define SDL_GetWindowSize(win, w, h) ((SDL_Window*)win)->GetSize(w, h)
+
+#define SDL_GL_GetDrawableSize(win, w, h) ((SDL_Window*)win)->GLGetDrawableSize(w, h)
+#define SDL_GL_SwapWindow(win) ((SDL_Window*)win)->GLSwap()
+#define SDL_GL_CreateContext(win) ((SDL_Window*)win)->GLCreateContext()
+
+typedef struct SDL_Renderer {
+	void (*Destroy)(void);
+	void (*Present)(void);
+} SDL_Renderer;
+
+SDL_Renderer* SDL_CreateRenderer(SDL_Window* window, Sint32 index, Uint32 flags);
+
+#define SDL_RenderPresent(r) ((SDL_Renderer*)r)->Present()
+#define SDL_DestroyRenderer(r) ((SDL_Renderer*)r)->Destroy()
+
+char *SDL_itoa(Sint32 value, char *str, Sint32 radix);
+char *SDL_uitoa(Uint32 value, char *str, Sint32 radix);
+void SDL_Delay(Uint32 ms);
+
+typedef struct SDL_mutex {
+	void (*Lock)(void);
+	void (*Unlock)(void);
+	void (*Destroy)(void);
+} SDL_mutex;
+
+SDL_mutex* SDL_CreateMutex(void);
+
+#define SDL_DestroyMutex(m) ((SDL_mutex*)m)->Destroy()
+#define SDL_LockMutex(m) ((SDL_mutex*)m)->Lock()
+#define SDL_UnlockMutex(m) ((SDL_mutex*)m)->Unlock()
+
+
+typedef struct SDL_Surface {
+    Sint32 w, h;
+    Sint32 pitch;
+    void* pixels;
+    SDL_Rect clip_rect;
+
+	Sint32 (*Lock)(void);
+	void (*Unlock)(void);
+	void (*Free)(void);
+	Sint32 (*SetColorKey)(Sint32 flag, Uint32 key);
+	void (*GetClipRect)(SDL_Rect* rect);
+	Sint32 (*SetBlendMode)(SDL_BlendMode blendMode);
+} SDL_Surface;
+
+SDL_Surface* SDL_CreateRGBSurfaceWithFormat(Uint32 flags, Sint32 width, Sint32 height, Sint32 depth, Uint32 format);
+
+#define SDL_LockSurface(s) ((SDL_Surface*)s)->Lock()
+#define SDL_UnlockSurface(s) ((SDL_Surface*)s)->Unlock()
+#define SDL_FreeSurface(s) ((SDL_Surface*)s)->Free()
+#define SDL_SetColorKey(s, f, k) ((SDL_Surface*)s)->SetColorKey(f, k)
+#define SDL_GetClipRect(s, r) ((SDL_Surface*)s)->GetClipRect(r)
+#define SDL_SetSurfaceBlendMode(s, m) ((SDL_Surface*)s)->SetBlendMode(m)
+Sint32 SDL_BlitSurface(SDL_Surface* src, const SDL_Rect* srcrect, SDL_Surface* dst, SDL_Rect* dstrect);
+Sint32 SDL_BlitScaled(SDL_Surface* src, const SDL_Rect* srcrect, SDL_Surface* dst, SDL_Rect* dstrect);
+
+typedef struct SDL_Texture {
+	void (*Destroy)(void);
+} SDL_Texture;
+SDL_Texture* SDL_CreateTextureFromSurface(SDL_Renderer* renderer, SDL_Surface*  surface);
+#define SDL_DestroyTexture(t) ((SDL_Texture*)t)->Destroy()
+
+Sint32 SDL_RenderCopy(SDL_Renderer* renderer, SDL_Texture* texture, const SDL_Rect* srcrect, const SDL_Rect* dstrect);
+
+
+Sint32 SDL_GL_SetSwapInterval(Sint32 interval);
+void SDL_GL_DeleteContext(SDL_GLContext context);
+Sint32 SDL_Init(Uint32 flags);
+Sint32 SDL_PollEvent(SDL_Event* event);
+void SDL_StartTextInput(void);
+void SDL_StopTextInput(void);
+SDL_Keymod SDL_GetModState(void);
+Sint32 SDL_SetRelativeMouseMode(SDL_bool enabled);
+Uint8 SDL_GetEventState(Uint32 type);
+Uint32 SDL_GetGlobalMouseState(int* x, int* y);
+Sint32 SDL_GetDisplayBounds(Sint32 displayIndex, SDL_Rect* rect);
+
+typedef Uint32 (*SDL_TimerCallback)(Uint32 interval, void* param);
+SDL_TimerID SDL_AddTimer(Uint32 interval, SDL_TimerCallback callback, void* param);
+SDL_bool SDL_RemoveTimer(SDL_TimerID id);
\ No newline at end of file
diff --git a/libs/includes/SDL2/SDL_opengl.h b/libs/includes/SDL2/SDL_opengl.h
new file mode 100644
index 0000000..e69de29
diff --git a/libs/includes/SDL2/SDL_opengl_glext.h b/libs/includes/SDL2/SDL_opengl_glext.h
new file mode 100644
index 0000000..e69de29
diff --git a/libs/includes/SDL2/SDL_stdinc.h b/libs/includes/SDL2/SDL_stdinc.h
new file mode 100644
index 0000000..e69de29
diff --git a/libs/includes/arpa_inet.h b/libs/includes/arpa/inet.h
similarity index 100%
rename from libs/includes/arpa_inet.h
rename to libs/includes/arpa/inet.h
diff --git a/libs/includes/ctype.h b/libs/includes/ctype.h
new file mode 100644
index 0000000..83e1371
--- /dev/null
+++ b/libs/includes/ctype.h
@@ -0,0 +1,15 @@
+_cxgo_go_bool isalnum(_cxgo_go_rune);
+_cxgo_go_bool isalpha(_cxgo_go_rune);
+_cxgo_go_bool isascii(_cxgo_go_rune);
+_cxgo_go_bool iscntrl(_cxgo_go_rune);
+_cxgo_go_bool isdigit(_cxgo_go_rune);
+_cxgo_go_bool isgraph(_cxgo_go_rune);
+_cxgo_go_bool islower(_cxgo_go_rune);
+_cxgo_go_bool isprint(_cxgo_go_rune);
+_cxgo_go_bool ispunct(_cxgo_go_rune);
+_cxgo_go_bool isspace(_cxgo_go_rune);
+_cxgo_go_bool isupper(_cxgo_go_rune);
+_cxgo_go_bool isxdigit(_cxgo_go_rune);
+_cxgo_go_rune toascii(_cxgo_go_rune);
+_cxgo_go_rune tolower(_cxgo_go_rune);
+_cxgo_go_rune toupper(_cxgo_go_rune);
\ No newline at end of file
diff --git a/libs/includes/embed/dirent.h b/libs/includes/dirent.h
similarity index 100%
rename from libs/includes/embed/dirent.h
rename to libs/includes/dirent.h
diff --git a/libs/includes/embed/fcntl.h b/libs/includes/fcntl.h
similarity index 100%
rename from libs/includes/embed/fcntl.h
rename to libs/includes/fcntl.h
diff --git a/libs/includes/fenv.h b/libs/includes/fenv.h
new file mode 100644
index 0000000..4014f3e
--- /dev/null
+++ b/libs/includes/fenv.h
@@ -0,0 +1,2 @@
+const _cxgo_go_int FE_TOWARDZERO = 1;
+_cxgo_sint32 fesetround(_cxgo_sint32 round);
\ No newline at end of file
diff --git a/libs/includes/embed/float.h b/libs/includes/float.h
similarity index 100%
rename from libs/includes/embed/float.h
rename to libs/includes/float.h
diff --git a/libs/includes/embed/getopt.h b/libs/includes/getopt.h
similarity index 100%
rename from libs/includes/embed/getopt.h
rename to libs/includes/getopt.h
diff --git a/libs/includes/embed/inttypes.h b/libs/includes/inttypes.h
similarity index 100%
rename from libs/includes/embed/inttypes.h
rename to libs/includes/inttypes.h
diff --git a/libs/includes/embed/libgen.h b/libs/includes/libgen.h
similarity index 100%
rename from libs/includes/embed/libgen.h
rename to libs/includes/libgen.h
diff --git a/libs/includes/pthread.h b/libs/includes/pthread.h
index 6da4259..9e1e009 100644
--- a/libs/includes/pthread.h
+++ b/libs/includes/pthread.h
@@ -1,4 +1,3 @@
-#include <cxgo_builtin.h>
 #include <time.h>
 
 const _cxgo_go_int PTHREAD_MUTEX_RECURSIVE = 1;
diff --git a/libs/includes/embed/sched.h b/libs/includes/sched.h
similarity index 100%
rename from libs/includes/embed/sched.h
rename to libs/includes/sched.h
diff --git a/libs/includes/embed/semaphore.h b/libs/includes/semaphore.h
similarity index 100%
rename from libs/includes/embed/semaphore.h
rename to libs/includes/semaphore.h
diff --git a/libs/includes/setjmp.h b/libs/includes/setjmp.h
index 0cc4220..8904ace 100644
--- a/libs/includes/setjmp.h
+++ b/libs/includes/setjmp.h
@@ -1,5 +1,3 @@
-#include <cxgo_builtin.h>
-
 typedef struct jmp_buf {
 	_cxgo_go_int (*SetJump) ();
 	void (*LongJump) (_cxgo_go_int);
diff --git a/libs/includes/embed/signal.h b/libs/includes/signal.h
similarity index 100%
rename from libs/includes/embed/signal.h
rename to libs/includes/signal.h
diff --git a/libs/includes/stdarg.h b/libs/includes/stdarg.h
index ad67a19..95d92be 100644
--- a/libs/includes/stdarg.h
+++ b/libs/includes/stdarg.h
@@ -1,5 +1,3 @@
-#include <cxgo_builtin.h>
-
 #define va_list __builtin_va_list
 #define va_start(va, t) va.Start(t, _rest)
 #define va_arg(va, typ) (typ)(va.Arg())
diff --git a/libs/includes/stdlib.h b/libs/includes/stdlib.h
index b5ba35f..6355e46 100644
--- a/libs/includes/stdlib.h
+++ b/libs/includes/stdlib.h
@@ -1,4 +1,3 @@
-#include <cxgo_builtin.h>
 #include <stddef.h>
 
 #define EXIT_FAILURE 1
diff --git a/libs/includes/string.h b/libs/includes/string.h
index 188f819..5dc0ee6 100644
--- a/libs/includes/string.h
+++ b/libs/includes/string.h
@@ -1,4 +1,3 @@
-#include <cxgo_builtin.h>
 #include <stddef.h>
 #include <stdlib.h>
 
diff --git a/libs/includes/embed/strings.h b/libs/includes/strings.h
similarity index 100%
rename from libs/includes/embed/strings.h
rename to libs/includes/strings.h
diff --git a/libs/includes/embed/sys/mkdev.h b/libs/includes/sys/mkdev.h
similarity index 100%
rename from libs/includes/embed/sys/mkdev.h
rename to libs/includes/sys/mkdev.h
diff --git a/libs/includes/sys_socket.h b/libs/includes/sys/socket.h
similarity index 100%
rename from libs/includes/sys_socket.h
rename to libs/includes/sys/socket.h
diff --git a/libs/includes/sys_stat.h b/libs/includes/sys/stat.h
similarity index 100%
rename from libs/includes/sys_stat.h
rename to libs/includes/sys/stat.h
diff --git a/libs/includes/sys_time.h b/libs/includes/sys/time.h
similarity index 100%
rename from libs/includes/sys_time.h
rename to libs/includes/sys/time.h
diff --git a/libs/includes/sys_types.h b/libs/includes/sys/types.h
similarity index 95%
rename from libs/includes/sys_types.h
rename to libs/includes/sys/types.h
index 8fec000..3a21dd9 100644
--- a/libs/includes/sys_types.h
+++ b/libs/includes/sys/types.h
@@ -1,4 +1,3 @@
-#include <cxgo_builtin.h>
 #include <stddef.h>
 #include <time.h>
 
diff --git a/libs/includes/time.h b/libs/includes/time.h
index 458c9b9..0bbb12b 100644
--- a/libs/includes/time.h
+++ b/libs/includes/time.h
@@ -1,4 +1,3 @@
-#include <cxgo_builtin.h>
 #include <sys/types.h>
 
 const _cxgo_go_int CLOCK_REALTIME = 0;
diff --git a/libs/includes/unistd.h b/libs/includes/unistd.h
index 5628cbe..9813e29 100644
--- a/libs/includes/unistd.h
+++ b/libs/includes/unistd.h
@@ -1,4 +1,3 @@
-#include <cxgo_builtin.h>
 #include <stdlib.h>
 #include <sys/types.h>
 #include <sys/stat.h>
diff --git a/libs/includes/wctype.h b/libs/includes/wctype.h
index 2b182e8..2669dee 100644
--- a/libs/includes/wctype.h
+++ b/libs/includes/wctype.h
@@ -1,5 +1,3 @@
-//#include <cxgo_builtin.h>
-
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdio.h>
diff --git a/libs/includes/embed/windows.h b/libs/includes/windows.h
similarity index 100%
rename from libs/includes/embed/windows.h
rename to libs/includes/windows.h
diff --git a/libs/math.go b/libs/math.go
index 6f30f2a..74ef97c 100644
--- a/libs/math.go
+++ b/libs/math.go
@@ -18,7 +18,6 @@ func init() {
 		doubleT := types.FloatT(8)
 		floatT := types.FloatT(4)
 		var buf bytes.Buffer
-		buf.WriteString("#include <" + BuiltinH + ">\n")
 		buf.WriteString("const double M_PI = 3.1415;\n")
 		lib := &Library{
 			Imports: map[string]string{
diff --git a/libs/netdb.go b/libs/netdb.go
index a1c9074..4b8ae82 100644
--- a/libs/netdb.go
+++ b/libs/netdb.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/runtime/cnet"
 	"github.com/gotranspile/cxgo/types"
 )
@@ -11,9 +9,6 @@ const (
 	netdbH = "netdb.h"
 )
 
-//go:embed includes/netdb.h
-var hnetdb string
-
 func init() {
 	RegisterLibrary(netdbH, func(c *Env) *Library {
 		strT := c.C().String()
@@ -35,8 +30,6 @@ func init() {
 			Idents: map[string]*types.Ident{
 				"gethostbyname": c.NewIdent("gethostbyname", "cnet.GetHostByName", cnet.GetHostByName, c.FuncTT(c.PtrT(hostentT), strT)),
 			},
-			// TODO
-			Header: hnetdb,
 		}
 	})
 }
diff --git a/libs/pthread.go b/libs/pthread.go
index 18d9f38..fbd38f9 100644
--- a/libs/pthread.go
+++ b/libs/pthread.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/runtime/pthread"
 	"github.com/gotranspile/cxgo/types"
 )
@@ -11,9 +9,6 @@ const (
 	pthreadH = "pthread.h"
 )
 
-//go:embed includes/pthread.h
-var hpthread string
-
 func init() {
 	RegisterLibrary(pthreadH, func(c *Env) *Library {
 		gintT := c.Go().Int()
@@ -70,8 +65,6 @@ func init() {
 				"pthread_cond_init":       c.NewIdent("pthread_cond_init", "pthread.CondInit", pthread.CondInit, c.FuncTT(intT, c.PtrT(condT), c.PtrT(condAttrT))),
 				"pthread_cond_destroy":    c.NewIdent("pthread_cond_destroy", "pthread.CondFree", pthread.CondFree, c.FuncTT(intT, c.PtrT(condT))),
 			},
-			// TODO
-			Header: hpthread,
 		}
 	})
 }
diff --git a/libs/registry.go b/libs/registry.go
index 8fabb28..b883057 100644
--- a/libs/registry.go
+++ b/libs/registry.go
@@ -107,11 +107,16 @@ func cTypeStr(t types.Type) string {
 	}
 }
 
-var libs = make(map[string]LibraryFunc)
+var (
+	libs   = make(map[string]LibraryFunc)
+	libsrc = make(map[string]string)
+)
 
 type LibraryFunc func(c *Env) *Library
 
 // RegisterLibrary registers an override for a C library.
+//
+// If the library provides no custom cxgo identifiers or types, RegisterLibrarySrc can be used instead.
 func RegisterLibrary(name string, fnc LibraryFunc) {
 	if name == "" {
 		panic("empty name")
@@ -125,6 +130,19 @@ func RegisterLibrary(name string, fnc LibraryFunc) {
 	libs[name] = fnc
 }
 
+// RegisterLibrarySrc registers an override for a C library source.
+//
+// For registering custom cxgo identifiers or types see RegisterLibrary.
+func RegisterLibrarySrc(name string, hdr string) {
+	if name == "" {
+		panic("empty name")
+	}
+	if _, ok := libsrc[name]; ok {
+		panic("already registered")
+	}
+	libsrc[name] = hdr
+}
+
 const IncludePath = "/_cxgo_overrides"
 
 var defPathReplacer = strings.NewReplacer(
@@ -134,14 +152,19 @@ var defPathReplacer = strings.NewReplacer(
 
 // GetLibrary finds or initializes the library, given a C include filename.
 func (c *Env) GetLibrary(name string) (*Library, bool) {
-	if l, ok := c.libs[name]; ok {
+	l, ok := c.libs[name]
+	if ok {
 		return l, true
 	}
-	fnc, ok := libs[name]
-	if !ok {
+	// First consult a general library registry.
+	// If not found, but we have a library source - register library anyway.
+	if fnc, ok := libs[name]; ok {
+		l = fnc(c)
+	} else if _, ok := libsrc[name]; ok {
+		l = new(Library)
+	} else {
 		return nil, false
 	}
-	l := fnc(c)
 	l.created = true
 	l.Name = name
 	//for name, typ := range l.Types {
@@ -163,21 +186,24 @@ func (c *Env) GetLibrary(name string) (*Library, bool) {
 	for k, v := range l.ForceMacros {
 		c.macros[k] = v
 	}
-
 	ifdef := "_cxgo_" + strings.ToUpper(defPathReplacer.Replace(name))
-	l.Header = fmt.Sprintf(`
-#ifndef %s
-#define %s
-
-%s
-
-#endif // %s
-`,
-		ifdef,
-		ifdef,
-		l.Header,
-		ifdef,
-	)
+	var hdr strings.Builder
+	hdr.WriteString("#ifndef " + ifdef + "\n")
+	hdr.WriteString("#define " + ifdef + "\n")
+	if name != BuiltinH {
+		hdr.WriteString("#include <" + BuiltinH + ">\n")
+	}
+	hdr.WriteString("\n")
+	if src := libsrc[name]; src != "" {
+		hdr.WriteString(src)
+		hdr.WriteString("\n")
+	}
+	if l.Header != "" {
+		hdr.WriteString(l.Header)
+		hdr.WriteString("\n")
+	}
+	hdr.WriteString("\n#endif // " + ifdef + "\n")
+	l.Header = hdr.String()
 	return l, true
 }
 
diff --git a/libs/reglibs.go b/libs/reglibs.go
index 80faacb..012a6bf 100644
--- a/libs/reglibs.go
+++ b/libs/reglibs.go
@@ -2,16 +2,15 @@ package libs
 
 import (
 	"embed"
-	"fmt"
 	"io/fs"
 	"strings"
 )
 
-//go:embed includes/embed
+//go:embed includes
 var efs embed.FS
 
 func init() {
-	const root = "includes/embed"
+	const root = "includes"
 	err := fs.WalkDir(efs, root, func(path string, d fs.DirEntry, err error) error {
 		if err != nil {
 			return err
@@ -23,11 +22,7 @@ func init() {
 			return err
 		}
 		fname := strings.TrimPrefix(path, root+"/")
-		RegisterLibrary(fname, func(env *Env) *Library {
-			return &Library{
-				Header: fmt.Sprintf("#include <%s>\n%s", BuiltinH, string(data)),
-			}
-		})
+		RegisterLibrarySrc(fname, string(data))
 		return nil
 	})
 	if err != nil {
diff --git a/libs/sdl2.go b/libs/sdl2.go
index f885f96..53d2511 100644
--- a/libs/sdl2.go
+++ b/libs/sdl2.go
@@ -5,10 +5,7 @@ import (
 )
 
 const (
-	sdl2H          = "SDL2/SDL.h"
-	sdl2OpenGLH    = "SDL2/SDL_opengl.h"
-	sdl2OpenGLExtH = "SDL2/SDL_opengl_glext.h"
-	sdl2StdIncH    = "SDL2/SDL_stdinc.h"
+	sdl2H = "SDL2/SDL.h"
 )
 
 func init() {
@@ -195,265 +192,6 @@ func init() {
 				"SDL_WINDOW_OPENGL":             types.NewIdent("sdl.WINDOW_OPENGL", uintT),
 				"SDL_WINDOW_FULLSCREEN_DESKTOP": types.NewIdent("sdl.WINDOW_FULLSCREEN_DESKTOP", uintT),
 			},
-			// TODO
-			Header: `
-#include <` + BuiltinH + `>
-
-#define Uint32 _cxgo_uint32
-#define Uint16 _cxgo_uint16
-#define Uint8 _cxgo_uint8
-#define Sint32 _cxgo_sint32
-#define Sint16 _cxgo_sint16
-#define Sint8 _cxgo_sint8
-#define SDL_bool _cxgo_go_bool
-typedef Sint32 SDL_FingerID;
-typedef Sint32 SDL_Scancode;
-typedef Sint32 SDL_Keymod;
-typedef Sint32 SDL_BlendMode;
-typedef Sint32 SDL_TimerID;
-
-
-#define SDL_TRUE 1
-#define SDL_FALSE 0
-const Sint32 SDL_PIXELFORMAT_RGBA5551 = 1;
-const Sint32 SDL_PIXELFORMAT_RGB565 = 2;
-const Sint32 SDL_PIXELFORMAT_RGB555 = 3;
-
-const Sint32 SDL_RENDERER_ACCELERATED = 1;
-const Sint32 SDL_RENDERER_PRESENTVSYNC = 2;
-
-#define SDL_NUM_SCANCODES 512
-
-typedef struct{
-  Sint16 x, y;
-  Uint16 w, h;
-} SDL_Rect;
-
-#define SDL_TEXTEDITING 770
-#define SDL_TEXTINPUT 771
-#define SDL_KEYDOWN 768
-#define SDL_KEYUP 769
-#define SDL_MOUSEBUTTONDOWN 1025
-#define SDL_MOUSEBUTTONUP 1026
-#define SDL_MOUSEMOTION 1024
-#define SDL_MOUSEWHEEL 1027
-#define SDL_WINDOWEVENT 512
-
-#define SDL_WINDOWEVENT_FOCUS_LOST 13
-#define SDL_WINDOWEVENT_FOCUS_GAINED 12
-
-#define SDL_BUTTON_LEFT 1
-#define SDL_BUTTON_RIGHT 3
-#define SDL_BUTTON_MIDDLE 2
-
-const Sint32 SDL_PRESSED = 1;
-
-const Sint32 SDL_SCANCODE_SPACE = 1;
-const Sint32 KMOD_LSHIFT = 1;
-const Sint32 KMOD_RSHIFT = 2;
-const Sint32 KMOD_RALT = 3;
-
-const Uint32 SDL_INIT_VIDEO = 1;
-const Uint32 SDL_INIT_TIMER = 2;
-const Sint32 SDL_WINDOWPOS_UNDEFINED = -1;
-const Sint32 SDL_WINDOWPOS_CENTERED = -2;
-const Uint32 SDL_WINDOW_RESIZABLE = 1;
-const Uint32 SDL_WINDOW_OPENGL = 2;
-const SDL_BlendMode SDL_BLENDMODE_NONE = 1;
-
-typedef struct{
-    SDL_Scancode scancode;
-} SDL_Keysym;
-
-typedef struct{
-    SDL_Keysym keysym;
-    Uint8 state;
-} SDL_KeyboardEvent;
-
-typedef struct{
-    Uint8 button;
-    Uint8 state;
-    Sint32 x,y;
-} SDL_MouseButtonEvent;
-
-typedef struct{
-    Sint32 x, y;
-    Sint32 xrel, yrel;
-} SDL_MouseMotionEvent;
-
-typedef struct{
-    Sint32 x, y;
-} SDL_MouseWheelEvent;
-
-typedef struct{} SDL_TouchFingerEvent;
-
-typedef struct{
-    char text[32];
-} SDL_TextEditingEvent;
-
-typedef struct{
-    char text[32];
-} SDL_TextInputEvent;
-
-typedef struct{
-    Uint8 event;
-} SDL_WindowEvent;
-
-typedef struct{
-    int type;
-    SDL_TextEditingEvent edit;
-    SDL_TextInputEvent text;
-    SDL_KeyboardEvent key;
-    SDL_MouseButtonEvent button;
-    SDL_MouseMotionEvent motion;
-    SDL_MouseWheelEvent wheel;
-    SDL_WindowEvent window;
-} SDL_Event;
-
-const Uint32 SDL_WINDOW_FULLSCREEN_DESKTOP = 0;
-
-typedef struct SDL_GLContext {} SDL_GLContext;
-
-typedef struct SDL_Window {
-	Sint32 (*SetFullscreen)(Uint32 flags);
-	void (*GetSize)(Sint32 *w, Sint32 *h);
-	void (*GetPosition)(Sint32 *x, Sint32 *y);
-	void (*SetSize)(Sint32 w, Sint32 h);
-	void (*SetPosition)(Sint32 x, Sint32 y);
-	void (*Minimize)(void);
-	void (*Restore)(void);
-	void (*SetGrab)(SDL_bool);
-	void (*SetResizable)(SDL_bool);
-	void (*SetBordered)(SDL_bool);
-	void (*SetTitle)(const char*);
-	Sint32 (*GetDisplayIndex)(void);
-	void (*GLGetDrawableSize)(Sint32* w, Sint32* h);
-	void (*GLSwapWindow)(void);
-	SDL_GLContext (*GLCreateContext)(void);
-} SDL_Window;
-
-const char* SDL_GetError(void);
-
-Uint32 SDL_GetTicks(void);
-SDL_Window* SDL_CreateWindow(const char* title, Sint32 x, Sint32 y, Sint32 w, Sint32 h, Uint32 flags);
-#define SDL_SetWindowFullscreen(win, flags) ((SDL_Window*)win)->SetFullscreen(flags)
-#define SDL_SetWindowSize(win, w, h) ((SDL_Window*)win)->SetSize(w, h)
-#define SDL_SetWindowPosition(win, x, y) ((SDL_Window*)win)->SetPosition(x, y)
-#define SDL_SetWindowGrab(win, v) ((SDL_Window*)win)->SetGrab(v)
-#define SDL_SetWindowTitle(win, v) ((SDL_Window*)win)->SetTitle(v)
-#define SDL_MinimizeWindow(win) ((SDL_Window*)win)->Minimize()
-#define SDL_RestoreWindow(win) ((SDL_Window*)win)->Restore()
-#define SDL_GetWindowDisplayIndex(win) ((SDL_Window*)win)->GetDisplayIndex()
-#define SDL_SetWindowResizable(win, v) ((SDL_Window*)win)->SetResizable(v)
-#define SDL_SetWindowBordered(win, v) ((SDL_Window*)win)->SetBordered(v)
-#define SDL_GetWindowPosition(win, x, y) ((SDL_Window*)win)->GetPosition(x, y)
-#define SDL_GetWindowSize(win, w, h) ((SDL_Window*)win)->GetSize(w, h)
-
-#define SDL_GL_GetDrawableSize(win, w, h) ((SDL_Window*)win)->GLGetDrawableSize(w, h)
-#define SDL_GL_SwapWindow(win) ((SDL_Window*)win)->GLSwap()
-#define SDL_GL_CreateContext(win) ((SDL_Window*)win)->GLCreateContext()
-
-typedef struct SDL_Renderer {
-	void (*Destroy)(void);
-	void (*Present)(void);
-} SDL_Renderer;
-
-SDL_Renderer* SDL_CreateRenderer(SDL_Window* window, Sint32 index, Uint32 flags);
-
-#define SDL_RenderPresent(r) ((SDL_Renderer*)r)->Present()
-#define SDL_DestroyRenderer(r) ((SDL_Renderer*)r)->Destroy()
-
-char *SDL_itoa(Sint32 value, char *str, Sint32 radix);
-char *SDL_uitoa(Uint32 value, char *str, Sint32 radix);
-void SDL_Delay(Uint32 ms);
-
-typedef struct SDL_mutex {
-	void (*Lock)(void);
-	void (*Unlock)(void);
-	void (*Destroy)(void);
-} SDL_mutex;
-
-SDL_mutex* SDL_CreateMutex(void);
-
-#define SDL_DestroyMutex(m) ((SDL_mutex*)m)->Destroy()
-#define SDL_LockMutex(m) ((SDL_mutex*)m)->Lock()
-#define SDL_UnlockMutex(m) ((SDL_mutex*)m)->Unlock()
-
-
-typedef struct SDL_Surface {
-    Sint32 w, h;
-    Sint32 pitch;
-    void* pixels;
-    SDL_Rect clip_rect;
-
-	Sint32 (*Lock)(void);
-	void (*Unlock)(void);
-	void (*Free)(void);
-	Sint32 (*SetColorKey)(Sint32 flag, Uint32 key);
-	void (*GetClipRect)(SDL_Rect* rect);
-	Sint32 (*SetBlendMode)(SDL_BlendMode blendMode);
-} SDL_Surface;
-
-SDL_Surface* SDL_CreateRGBSurfaceWithFormat(Uint32 flags, Sint32 width, Sint32 height, Sint32 depth, Uint32 format);
-
-#define SDL_LockSurface(s) ((SDL_Surface*)s)->Lock()
-#define SDL_UnlockSurface(s) ((SDL_Surface*)s)->Unlock()
-#define SDL_FreeSurface(s) ((SDL_Surface*)s)->Free()
-#define SDL_SetColorKey(s, f, k) ((SDL_Surface*)s)->SetColorKey(f, k)
-#define SDL_GetClipRect(s, r) ((SDL_Surface*)s)->GetClipRect(r)
-#define SDL_SetSurfaceBlendMode(s, m) ((SDL_Surface*)s)->SetBlendMode(m)
-Sint32 SDL_BlitSurface(SDL_Surface* src, const SDL_Rect* srcrect, SDL_Surface* dst, SDL_Rect* dstrect);
-Sint32 SDL_BlitScaled(SDL_Surface* src, const SDL_Rect* srcrect, SDL_Surface* dst, SDL_Rect* dstrect);
-
-typedef struct SDL_Texture {
-	void (*Destroy)(void);
-} SDL_Texture;
-SDL_Texture* SDL_CreateTextureFromSurface(SDL_Renderer* renderer, SDL_Surface*  surface);
-#define SDL_DestroyTexture(t) ((SDL_Texture*)t)->Destroy()
-
-Sint32 SDL_RenderCopy(SDL_Renderer* renderer, SDL_Texture* texture, const SDL_Rect* srcrect, const SDL_Rect* dstrect);
-
-
-Sint32 SDL_GL_SetSwapInterval(Sint32 interval);
-void SDL_GL_DeleteContext(SDL_GLContext context);
-Sint32 SDL_Init(Uint32 flags);
-Sint32 SDL_PollEvent(SDL_Event* event);
-void SDL_StartTextInput(void);
-void SDL_StopTextInput(void);
-SDL_Keymod SDL_GetModState(void);
-Sint32 SDL_SetRelativeMouseMode(SDL_bool enabled);
-Uint8 SDL_GetEventState(Uint32 type);
-Uint32 SDL_GetGlobalMouseState(int* x, int* y);
-Sint32 SDL_GetDisplayBounds(Sint32 displayIndex, SDL_Rect* rect);
-
-typedef Uint32 (*SDL_TimerCallback)(Uint32 interval, void* param);
-SDL_TimerID SDL_AddTimer(Uint32 interval, SDL_TimerCallback callback, void* param);
-SDL_bool SDL_RemoveTimer(SDL_TimerID id);
-`,
-		}
-	})
-	RegisterLibrary(sdl2OpenGLH, func(c *Env) *Library {
-		return &Library{
-			// TODO
-			Header: `
-#include <` + BuiltinH + `>
-`,
-		}
-	})
-	RegisterLibrary(sdl2OpenGLExtH, func(c *Env) *Library {
-		return &Library{
-			// TODO
-			Header: `
-#include <` + BuiltinH + `>
-`,
-		}
-	})
-	RegisterLibrary(sdl2StdIncH, func(c *Env) *Library {
-		return &Library{
-			// TODO
-			Header: `
-#include <` + BuiltinH + `>
-`,
 		}
 	})
 }
diff --git a/libs/setjmp.go b/libs/setjmp.go
index 3119ac2..8d135b9 100644
--- a/libs/setjmp.go
+++ b/libs/setjmp.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/types"
 )
 
@@ -10,9 +8,6 @@ const (
 	setjmpH = "setjmp.h"
 )
 
-//go:embed includes/setjmp.h
-var hsetjmp string
-
 func init() {
 	RegisterLibrary(setjmpH, func(c *Env) *Library {
 		gint := c.Go().Int()
@@ -27,7 +22,6 @@ func init() {
 			Imports: map[string]string{
 				"libc": RuntimeLibc,
 			},
-			Header: hsetjmp,
 		}
 	})
 }
diff --git a/libs/stdarg.go b/libs/stdarg.go
index a2ddfbe..44e6bbd 100644
--- a/libs/stdarg.go
+++ b/libs/stdarg.go
@@ -1,19 +1,13 @@
 package libs
 
-import _ "embed"
-
 const (
 	StdargH = "stdarg.h"
 )
 
-//go:embed includes/stdarg.h
-var hstdarg string
-
 func init() {
 	RegisterLibrary(StdargH, func(c *Env) *Library {
 		// all types and method are define as builtins, so only macros here
 		l := &Library{
-			Header: hstdarg,
 			Imports: map[string]string{
 				"libc": RuntimeLibc,
 			},
diff --git a/libs/stdarg_test.go b/libs/stdarg_test.go
index 14817b5..a6ae8a8 100644
--- a/libs/stdarg_test.go
+++ b/libs/stdarg_test.go
@@ -3,14 +3,13 @@ package libs
 import (
 	"testing"
 
-	"github.com/gotranspile/cxgo/types"
 	"github.com/stretchr/testify/require"
+
+	"github.com/gotranspile/cxgo/types"
 )
 
-var expStdArgsH = `
-#ifndef _cxgo_STDARG_H
+var expStdArgsH = `#ifndef _cxgo_STDARG_H
 #define _cxgo_STDARG_H
-
 #include <cxgo_builtin.h>
 
 #define va_list __builtin_va_list
diff --git a/libs/stdint.go b/libs/stdint.go
index 6c87d56..63118ba 100644
--- a/libs/stdint.go
+++ b/libs/stdint.go
@@ -156,7 +156,6 @@ var (
 
 func incStdInt(e *types.Env, m map[string]*types.Ident) string {
 	var buf strings.Builder
-	buf.WriteString("#include <" + BuiltinH + ">\n")
 	buf.WriteString(fixedIntTypes())
 	buf.WriteString(maxIntTypes(e))
 	buf.WriteString(intLimits(m))
diff --git a/libs/stdint_test.go b/libs/stdint_test.go
index 4ceef46..1ab7527 100644
--- a/libs/stdint_test.go
+++ b/libs/stdint_test.go
@@ -4,17 +4,19 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/gotranspile/cxgo/types"
 	"github.com/stretchr/testify/require"
+
+	"github.com/gotranspile/cxgo/types"
 )
 
 func TestStdInt(t *testing.T) {
-	c := types.NewEnv(types.Config32())
-	s := incStdInt(c, nil)
-	s = strings.TrimSpace(s)
-	s = strings.TrimSpace(s)
-	require.Equal(t, strings.TrimSpace(`
+	c := NewEnv(types.Config32())
+	l, ok := c.GetLibrary(stdintH)
+	require.True(t, ok)
+	require.Equal(t, strings.TrimSpace(`#ifndef _cxgo_STDINT_H
+#define _cxgo_STDINT_H
 #include <cxgo_builtin.h>
+
 #define int8_t _cxgo_sint8
 #define int16_t _cxgo_sint16
 #define int32_t _cxgo_sint32
@@ -108,5 +110,9 @@ typedef _cxgo_uint64 uintmax_t;
 
 #define WINT_MIN 0
 #define WINT_MAX 4294967295u
-`), strings.TrimSpace(s))
+
+
+
+#endif // _cxgo_STDINT_H
+`), strings.TrimSpace(l.Header))
 }
diff --git a/libs/stdio.go b/libs/stdio.go
index a8c3936..3983d6f 100644
--- a/libs/stdio.go
+++ b/libs/stdio.go
@@ -58,7 +58,6 @@ func init() {
 				"_cxgo_EOF": c.NewIdent("_cxgo_EOF", "stdio.EOF", stdio.EOF, types.UntypedIntT(1)),
 			},
 			Header: `
-#include <` + BuiltinH + `>
 #include <` + stddefH + `>
 #include <` + StdargH + `>
 #include <` + StdlibH + `>
diff --git a/libs/stdlib.go b/libs/stdlib.go
index 4fbb54a..370cb0a 100644
--- a/libs/stdlib.go
+++ b/libs/stdlib.go
@@ -1,7 +1,6 @@
 package libs
 
 import (
-	_ "embed"
 	"fmt"
 	"os"
 
@@ -12,9 +11,6 @@ import (
 
 const StdlibH = "stdlib.h"
 
-//go:embed includes/stdlib.h
-var hstdlib string
-
 // https://pubs.opengroup.org/onlinepubs/9699919799/
 
 func init() {
@@ -48,7 +44,7 @@ func init() {
 				"bsearch":  c.NewIdent("bsearch", "libc.Search", libc.Search, c.FuncTT(voidPtr, voidPtr, voidPtr, uintT, uintT, c.FuncTT(intT, voidPtr, voidPtr))),
 				"mbstowcs": c.NewIdent("mbstowcs", "libc.Mbstowcs", libc.Mbstowcs, c.FuncTT(uintT, wstrT, cstrT, uintT)),
 			},
-			Header: hstdlib + fmt.Sprintf("#define RAND_MAX %d\n", libc.RandMax),
+			Header: fmt.Sprintf("#define RAND_MAX %d\n", libc.RandMax),
 		}
 
 		l.Declare(
diff --git a/libs/string.go b/libs/string.go
index 6f8f5d1..dc6d637 100644
--- a/libs/string.go
+++ b/libs/string.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/runtime/libc"
 	"github.com/gotranspile/cxgo/types"
 )
@@ -13,9 +11,6 @@ const (
 	stringH = "string.h"
 )
 
-//go:embed includes/string.h
-var hstring string
-
 func init() {
 	// TODO: should include <locale.h>
 	RegisterLibrary(stringH, func(c *Env) *Library {
@@ -45,7 +40,6 @@ func init() {
 				"strspn":      c.NewIdent("strspn", "libc.StrSpn", libc.StrSpn, c.FuncTT(gintT, cstrT, cstrT)),
 				"strcspn":     c.NewIdent("strcspn", "libc.StrCSpn", libc.StrCSpn, c.FuncTT(gintT, cstrT, cstrT)),
 			},
-			Header: hstring,
 		}
 	})
 }
diff --git a/libs/sys_socket.go b/libs/sys_socket.go
index 1f83bd5..7be34d0 100644
--- a/libs/sys_socket.go
+++ b/libs/sys_socket.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/runtime/cnet"
 	"github.com/gotranspile/cxgo/types"
 )
@@ -11,9 +9,6 @@ const (
 	sysSocketH = "sys/socket.h"
 )
 
-//go:embed includes/sys_socket.h
-var hsys_socket string
-
 func init() {
 	RegisterLibrary(sysSocketH, func(c *Env) *Library {
 		intT := types.IntT(4)
@@ -59,8 +54,6 @@ func init() {
 				"socket":       c.NewIdent("socket", "cnet.Socket", cnet.Socket, c.FuncTT(gintT, gintT, gintT, gintT)),
 				"setsockopt":   c.NewIdent("setsockopt", "cnet.SetSockOpt", cnet.SetSockOpt, c.FuncTT(gintT, gintT, gintT, gintT, bytesT, gintT)),
 			},
-			// TODO
-			Header: hsys_socket,
 		}
 	})
 }
diff --git a/libs/sys_stat.go b/libs/sys_stat.go
index 0f65eb8..63cbdbf 100644
--- a/libs/sys_stat.go
+++ b/libs/sys_stat.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/runtime/csys"
 	"github.com/gotranspile/cxgo/types"
 )
@@ -11,9 +9,6 @@ const (
 	sysStatH = "sys/stat.h"
 )
 
-//go:embed includes/sys_stat.h
-var hsys_stat string
-
 func init() {
 	RegisterLibrary(sysStatH, func(c *Env) *Library {
 		intT := types.IntT(4)
@@ -49,8 +44,6 @@ func init() {
 				"mkdir":   c.NewIdent("mkdir", "csys.Mkdir", csys.Mkdir, c.FuncTT(intT, strT, modeT)),
 				"S_ISDIR": c.NewIdent("S_ISDIR", "csys.IsDir", csys.IsDir, c.FuncTT(intT, modeT)),
 			},
-			// TODO
-			Header: hsys_stat,
 		}
 	})
 }
diff --git a/libs/sys_time.go b/libs/sys_time.go
index 2305884..fbac461 100644
--- a/libs/sys_time.go
+++ b/libs/sys_time.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/runtime/csys"
 	"github.com/gotranspile/cxgo/types"
 )
@@ -11,9 +9,6 @@ const (
 	sysTimeH = "sys/time.h"
 )
 
-//go:embed includes/sys_time.h
-var hsys_time string
-
 func init() {
 	RegisterLibrary(sysTimeH, func(c *Env) *Library {
 		intT := types.IntT(4)
@@ -29,8 +24,6 @@ func init() {
 			Idents: map[string]*types.Ident{
 				"gettimeofday": c.NewIdent("gettimeofday", "csys.GetTimeOfDay", csys.GetTimeOfDay, c.FuncTT(intT, c.PtrT(timevalT), c.PtrT(nil))),
 			},
-			// TODO
-			Header: hsys_time,
 		}
 	})
 }
diff --git a/libs/sys_types.go b/libs/sys_types.go
index 4680a7e..f3440a5 100644
--- a/libs/sys_types.go
+++ b/libs/sys_types.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/runtime/csys"
 	"github.com/gotranspile/cxgo/types"
 )
@@ -11,9 +9,6 @@ const (
 	sysTypesH = "sys/types.h"
 )
 
-//go:embed includes/sys_types.h
-var hsysTypes string
-
 func init() {
 	RegisterLibrary(sysTypesH, func(c *Env) *Library {
 		intT := types.IntT(4)
@@ -26,8 +21,6 @@ func init() {
 				"O_EXCL":   c.NewIdent("O_EXCL", "csys.O_EXCL", csys.O_EXCL, intT),
 				"O_TRUNC":  c.NewIdent("O_TRUNC", "csys.O_TRUNC", csys.O_TRUNC, intT),
 			},
-			// TODO
-			Header: hsysTypes,
 		}
 	})
 }
diff --git a/libs/time.go b/libs/time.go
index 30ea762..5f42eb5 100644
--- a/libs/time.go
+++ b/libs/time.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/runtime/libc"
 	"github.com/gotranspile/cxgo/types"
 )
@@ -11,9 +9,6 @@ const (
 	timeH = "time.h"
 )
 
-//go:embed includes/time.h
-var htime string
-
 func init() {
 	RegisterLibrary(timeH, func(c *Env) *Library {
 		gintT := c.Go().Int()
@@ -71,8 +66,6 @@ func init() {
 				"CLOCK_MONOTONIC": c.NewIdent("CLOCK_MONOTONIC", "libc.CLOCK_MONOTONIC", libc.CLOCK_MONOTONIC, gintT),
 				"CLOCKS_PER_SEC":  c.NewIdent("CLOCKS_PER_SEC", "libc.CLOCKS_PER_SEC", libc.CLOCKS_PER_SEC, gintT),
 			},
-			// TODO
-			Header: htime,
 		}
 	})
 }
diff --git a/libs/unistd.go b/libs/unistd.go
index a66e155..d2fd34f 100644
--- a/libs/unistd.go
+++ b/libs/unistd.go
@@ -1,8 +1,6 @@
 package libs
 
 import (
-	_ "embed"
-
 	"github.com/gotranspile/cxgo/runtime/cnet"
 	"github.com/gotranspile/cxgo/runtime/stdio"
 	"github.com/gotranspile/cxgo/types"
@@ -12,9 +10,6 @@ const (
 	unistdH = "unistd.h"
 )
 
-//go:embed includes/unistd.h
-var hunistd string
-
 func init() {
 	RegisterLibrary(unistdH, func(c *Env) *Library {
 		modeT := c.GetLibraryType(sysStatH, "mode_t")
@@ -42,7 +37,6 @@ func init() {
 				"getcwd":      c.NewIdent("getcwd", "stdio.GetCwd", stdio.GetCwd, c.FuncTT(strT, strT, gintT)),
 				"gethostname": c.NewIdent("gethostname", "cnet.GetHostname", cnet.GetHostname, c.FuncTT(gintT, strT, gintT)),
 			},
-			Header: hunistd,
 		}
 	})
 }
diff --git a/libs/wctype.go b/libs/wctype.go
index e4f1d3f..cd8a22d 100644
--- a/libs/wctype.go
+++ b/libs/wctype.go
@@ -1,7 +1,6 @@
 package libs
 
 import (
-	_ "embed"
 	"unicode"
 
 	"github.com/gotranspile/cxgo/runtime/libc"
@@ -14,9 +13,6 @@ const (
 	wctypeH = "wctype.h"
 )
 
-//go:embed includes/wctype.h
-var hwctype string
-
 func init() {
 	RegisterLibrary(wctypeH, func(c *Env) *Library {
 		runeT := c.Go().Rune()
@@ -42,7 +38,6 @@ func init() {
 				"towlower": c.NewIdent("towlower", "unicode.ToLower", unicode.ToLower, toT),
 				"towupper": c.NewIdent("towupper", "unicode.ToUpper", unicode.ToUpper, toT),
 			},
-			Header: hwctype,
 		}
 	})
 }