diff --git a/pkgs/by-name/sp/speechd/package.nix b/pkgs/by-name/sp/speechd/package.nix
index 644004c68325..eb78efae1208 100644
--- a/pkgs/by-name/sp/speechd/package.nix
+++ b/pkgs/by-name/sp/speechd/package.nix
@@ -134,7 +134,7 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   postPatch = lib.optionalString withPico ''
-    substituteInPlace src/modules/pico.c --replace "/usr/share/pico/lang" "${picotts}/share/pico/lang"
+    substituteInPlace src/modules/pico.c --replace-fail "/usr/share/pico/lang" "${picotts}/share/pico/lang"
   '';
 
   installFlags = [