diff --git a/build/unix/mozilla-xpcom.pc.in b/build/unix/mozilla-xpcom.pc.in
index f6f4ec6af26d..ef9187f36a65 100644
--- a/build/unix/mozilla-xpcom.pc.in
+++ b/build/unix/mozilla-xpcom.pc.in
@@ -8,4 +8,4 @@ Description: The Mozilla Cross Platform Component Library
 Version: %MOZILLA_VERSION%
 Requires: mozilla-nspr = %MOZILLA_VERSION%
 Libs: -L${libdir} -lxpcom
-Cflags: -I${includedir}/xpcom -I${includedir}/string
+Cflags: -I${includedir} -I${includedir}/xpcom -I${includedir}/string