diff --git a/pkgs/development/libraries/webkit/default.nix b/pkgs/development/libraries/webkit/default.nix
index 4adc75813aac..d81109b0d6fb 100644
--- a/pkgs/development/libraries/webkit/default.nix
+++ b/pkgs/development/libraries/webkit/default.nix
@@ -41,7 +41,7 @@ rec {
   '') ["minInit" "doUnpack"];
 
   fixTypos = fullDepEntry (''
-    sed -e 's@WebCore/workers/DedicatedWorkerThread.h$@& \@' -i WebCore/GNUMakefile
+    sed -e 's@WebCore/workers/DedicatedWorkerThread.h$@& \\@' -i WebCore/GNUMakefile
   '') ["minInit" "doUnpack"];
 
   name = "webkit-" + version;