diff --git a/srcpkgs/llvm/template b/srcpkgs/llvm/template
index 85f54875d86..90b8d5387fa 100644
--- a/srcpkgs/llvm/template
+++ b/srcpkgs/llvm/template
@@ -43,6 +43,8 @@ if [ -z "$CROSS_BUILD" ]; then
 fi
 subpackages+=" lld lld-devel"
 
+CXXFLAGS="-D_GLIBCXX_USE_C99_STDIO=1 -D_GLIBCXX_USE_C99_STDLIB=1"
+
 post_extract() {
 	# patches
 	cd ${XBPS_BUILDDIR}/llvm-${version}.src