diff --git a/CHANGE_LOG b/CHANGE_LOG
index d8b79534..b7816ac1 100644
--- a/CHANGE_LOG
+++ b/CHANGE_LOG
@@ -1,6 +1,6 @@
 2021-XX-XX   2.1.3:
 -------------------
-
+  * Fix building with MSVC / Bullseye, #129
 
 2021-06-13   2.1.2:
 -------------------
diff --git a/bitarray/bitarray.h b/bitarray/bitarray.h
index 1597d0f9..095810dc 100644
--- a/bitarray/bitarray.h
+++ b/bitarray/bitarray.h
@@ -47,10 +47,16 @@ typedef struct {
 #define BITMASK(endian, i)  \
     (((char) 1) << ((endian) == ENDIAN_LITTLE ? ((i) % 8) : (7 - (i) % 8)))
 
+#ifdef _MSC_VER
+#define INLINE __inline
+#else
+#define INLINE inline
+#endif
+
 /* ------------ low level access to bits in bitarrayobject ------------- */
 
 #ifndef NDEBUG
-static inline int GETBIT(bitarrayobject *self, Py_ssize_t i)
+static INLINE int GETBIT(bitarrayobject *self, Py_ssize_t i)
 {
     assert(0 <= i && i < self->nbits);
     return ((self)->ob_item[(i) / 8] & BITMASK((self)->endian, i) ? 1 : 0);
@@ -60,7 +66,7 @@ static inline int GETBIT(bitarrayobject *self, Py_ssize_t i)
     ((self)->ob_item[(i) / 8] & BITMASK((self)->endian, i) ? 1 : 0)
 #endif
 
-static inline void
+static INLINE void
 setbit(bitarrayobject *self, Py_ssize_t i, int bit)
 {
     char *cp, mask;
@@ -76,7 +82,7 @@ setbit(bitarrayobject *self, Py_ssize_t i, int bit)
 
 /* sets unused padding bits (within last byte of buffer) to 0,
    and return the number of padding bits -- self->nbits is unchanged */
-static inline int
+static INLINE int
 setunused(bitarrayobject *self)
 {
     const char mask[16] = {
@@ -110,7 +116,7 @@ static const unsigned char bitcount_lookup[256] = {
 
 /* Interpret a PyObject (usually PyLong or PyBool) as a bit, return 0 or 1.
    On error, return -1 and set error message. */
-static inline int
+static INLINE int
 pybit_as_int(PyObject *v)
 {
     Py_ssize_t x;
diff --git a/bitarray/pythoncapi_compat.h b/bitarray/pythoncapi_compat.h
index 4b04ccea..d9de1818 100644
--- a/bitarray/pythoncapi_compat.h
+++ b/bitarray/pythoncapi_compat.h
@@ -260,8 +260,9 @@ PyObject_CallOneArg(PyObject *func, PyObject *arg)
 static inline int
 PyModule_AddObjectRef(PyObject *module, const char *name, PyObject *value)
 {
+    int res;
     Py_XINCREF(value);
-    int res = PyModule_AddObject(module, name, value);
+    res = PyModule_AddObject(module, name, value);
     if (res < 0) {
         Py_XDECREF(value);
     }