diff --git a/pkgs/by-name/ag/agg/package.nix b/pkgs/by-name/ag/agg/package.nix
index 698b2ff62037..0af697f604ce 100644
--- a/pkgs/by-name/ag/agg/package.nix
+++ b/pkgs/by-name/ag/agg/package.nix
@@ -36,7 +36,7 @@ stdenv.mkDerivation (finalAttrs: {
 
   postPatch = ''
     substituteInPlace include/agg_renderer_outline_aa.h \
-      --replace 'line_profile_aa& profile() {' 'const line_profile_aa& profile() {'
+      --replace-fail 'line_profile_aa& profile() {' 'const line_profile_aa& profile() {'
   '';
 
   # fix build with new automake, from Gentoo ebuild