diff --git a/pkgs/by-name/it/itstool/package.nix b/pkgs/by-name/it/itstool/package.nix
index d0c4869c6d84..2dcb01182a67 100644
--- a/pkgs/by-name/it/itstool/package.nix
+++ b/pkgs/by-name/it/itstool/package.nix
@@ -2,6 +2,7 @@
   stdenv,
   lib,
   fetchurl,
+  fetchpatch,
   python3,
   autoreconfHook,
 }:
@@ -15,6 +16,15 @@ stdenv.mkDerivation rec {
     hash = "sha256-a5p80poSu5VZj1dQ6HY87niDahogf4W3TYsydbJ+h8o=";
   };
 
+  patches = [
+    # https://github.com/itstool/itstool/pull/51
+    (fetchpatch {
+      name = "fix-insufficiently-quoted-regular-expressions-pr51";
+      url = "https://github.com/itstool/itstool/commit/19f9580f27aa261ea383b395fdef7e153f3f9e6d.patch";
+      hash = "sha256-5J4mRXQu24o2rqVtaXN/ETgj6A8R0Ym+YkZhqhZTzIc=";
+    })
+  ];
+
   strictDeps = true;
 
   postPatch = ''