diff --git a/src/libexpr/nix-expr.pc.in b/src/libexpr/nix-expr.pc.in
index 21b6c38dd..79f3e2f45 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
+Cflags: -I${includedir}/nix -std=c++14
diff --git a/src/libmain/nix-main.pc.in b/src/libmain/nix-main.pc.in
index de1bdf706..38bc85c48 100644
--- a/src/libmain/nix-main.pc.in
+++ b/src/libmain/nix-main.pc.in
@@ -6,4 +6,4 @@ Name: Nix
 Description: Nix Package Manager
 Version: @PACKAGE_VERSION@
 Libs: -L${libdir} -lnixmain
-Cflags: -I${includedir}/nix
+Cflags: -I${includedir}/nix -std=c++14
diff --git a/src/libstore/nix-store.pc.in b/src/libstore/nix-store.pc.in
index 3f1a2d83d..4a6b96da2 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${libdir} -lnixstore -lnixutil -lnixformat
-Cflags: -I${includedir}/nix
+Cflags: -I${includedir}/nix -std=c++14