diff --git a/srcpkgs/kwindowsystem/template b/srcpkgs/kwindowsystem/template
index a5a6457bd4..f7eb12c616 100644
--- a/srcpkgs/kwindowsystem/template
+++ b/srcpkgs/kwindowsystem/template
@@ -13,11 +13,6 @@ homepage="https://projects.kde.org/projects/frameworks/kwindowsystem"
 distfiles="http://download.kde.org/stable/frameworks/${version%.*}/${pkgname}-${version}.tar.xz"
 checksum=361eebfebc753019d3b507c5b758dfb878c032b41c9062930bc46239618e7fa5
 
-post_configure() {
-	# Replace -isystem with -I to avoid "#include_next <stdlib.h>" file not found
-	find -name flags.make -exec sed -i "{}" -e "s;-isystem;-I;g" \;
-}
-
 kwindowsystem-devel_package() {
 	short_desc+=" - development"
 	depends="${makedepends} ${sourcepkg}-${version}_${revision}"