diff --git a/Makefile b/Makefile
index c1a1ce2c738..42d11638b19 100644
--- a/Makefile
+++ b/Makefile
@@ -36,4 +36,4 @@ endif
 
 include mk/lib.mk
 
-GLOBAL_CXXFLAGS += -g -Wall -include config.h -std=c++17 -I src
+GLOBAL_CXXFLAGS += -g -Wall -include config.h -std=c++20 -I src
diff --git a/perl/Makefile b/perl/Makefile
index 708f868822b..2d759e6fc48 100644
--- a/perl/Makefile
+++ b/perl/Makefile
@@ -1,6 +1,6 @@
 makefiles = local.mk
 
-GLOBAL_CXXFLAGS += -g -Wall -std=c++17 -I ../src
+GLOBAL_CXXFLAGS += -g -Wall -std=c++20 -I ../src
 
 -include Makefile.config
 
diff --git a/src/libcmd/nix-cmd.pc.in b/src/libcmd/nix-cmd.pc.in
index 1761a9f418f..a21d93f1d78 100644
--- a/src/libcmd/nix-cmd.pc.in
+++ b/src/libcmd/nix-cmd.pc.in
@@ -6,4 +6,4 @@ Name: Nix
 Description: Nix Package Manager
 Version: @PACKAGE_VERSION@
 Libs: -L${libdir} -lnixcmd
-Cflags: -I${includedir}/nix -std=c++17
+Cflags: -I${includedir}/nix -std=c++20
diff --git a/src/libexpr/nix-expr.pc.in b/src/libexpr/nix-expr.pc.in
index 80f7a492b1a..95d452ca810 100644
--- a/src/libexpr/nix-expr.pc.in
+++ b/src/libexpr/nix-expr.pc.in
@@ -7,4 +7,4 @@ Description: Nix Package Manager
 Version: @PACKAGE_VERSION@
 Requires: nix-store bdw-gc
 Libs: -L${libdir} -lnixexpr
-Cflags: -I${includedir}/nix -std=c++17
+Cflags: -I${includedir}/nix -std=c++20
diff --git a/src/libmain/nix-main.pc.in b/src/libmain/nix-main.pc.in
index 37b03dcd42c..b46ce199080 100644
--- a/src/libmain/nix-main.pc.in
+++ b/src/libmain/nix-main.pc.in
@@ -6,4 +6,4 @@ Name: Nix
 Description: Nix Package Manager
 Version: @PACKAGE_VERSION@
 Libs: -L${libdir} -lnixmain
-Cflags: -I${includedir}/nix -std=c++17
+Cflags: -I${includedir}/nix -std=c++20
diff --git a/src/libstore/nix-store.pc.in b/src/libstore/nix-store.pc.in
index 6d67b1e0380..385169a1324 100644
--- a/src/libstore/nix-store.pc.in
+++ b/src/libstore/nix-store.pc.in
@@ -6,4 +6,4 @@ Name: Nix
 Description: Nix Package Manager
 Version: @PACKAGE_VERSION@
 Libs: -L${libdir} -lnixstore -lnixutil
-Cflags: -I${includedir}/nix -std=c++17
+Cflags: -I${includedir}/nix -std=c++20