diff --git a/dev-libs/uulib/uulib-0.5.20-r3.ebuild b/dev-libs/uulib/uulib-0.5.20-r3.ebuild
index 534c8f243343c..af1621b9a79bc 100644
--- a/dev-libs/uulib/uulib-0.5.20-r3.ebuild
+++ b/dev-libs/uulib/uulib-0.5.20-r3.ebuild
@@ -3,7 +3,7 @@
 
 EAPI=8
 
-inherit autotools
+inherit autotools flag-o-matic
 
 MY_P=uudeview-${PV}
 
@@ -26,6 +26,11 @@ src_prepare() {
 	eautoreconf
 }
 
+src_configure() {
+	append-cppflags -DPROTOTYPES # 943841
+	default
+}
+
 src_install() {
 	default
 	find "${D}" -name '*.la' -delete || die