diff --git a/media-libs/fontconfig/fontconfig-2.12.6.ebuild b/media-libs/fontconfig/fontconfig-2.12.6.ebuild
index 900c010607316..6cfcc3f9fb4a6 100644
--- a/media-libs/fontconfig/fontconfig-2.12.6.ebuild
+++ b/media-libs/fontconfig/fontconfig-2.12.6.ebuild
@@ -44,7 +44,7 @@ src_prepare() {
 	default
 	export GPERF=$(type -P true)  # avoid dependency on gperf, #631980
 	sed -i -e 's/FC_GPERF_SIZE_T="unsigned int"/FC_GPERF_SIZE_T=size_t/' \
-		configure.ac  # rest of gperf dependency fix, #631920
+		configure.ac || die # rest of gperf dependency fix, #631920
 	eautoreconf
 }