diff --git a/pkgs/development/libraries/libcutl/default.nix b/pkgs/development/libraries/libcutl/default.nix
index b13805aa37a..b3effb4ab1e 100644
--- a/pkgs/development/libraries/libcutl/default.nix
+++ b/pkgs/development/libraries/libcutl/default.nix
@@ -8,7 +8,7 @@ stdenv.mkDerivation rec {
     description = "C++ utility library from Code Synthesis";
     longDescription = ''
         libcutl is a C++ utility library.
-        It contains a collection of generic and independent components such as 
+        It contains a collection of generic and independent components such as
         meta-programming tests, smart pointers, containers, compiler building blocks, etc.
     '';
     homepage = "https://codesynthesis.com/projects/libcutl/";
@@ -18,7 +18,7 @@ stdenv.mkDerivation rec {
     license = licenses.mit;
   };
 
-  majmin = builtins.head ( builtins.match "([[:digit:]]\.[[:digit:]]+)\.*" "${version}" );
+  majmin = builtins.head ( builtins.match "([[:digit:]]\\.[[:digit:]]+).*" "${version}" );
   src = fetchurl {
     url = "https://codesynthesis.com/download/${pname}/${majmin}/${pname}-${version}.tar.bz2";
     sha256 = "070j2x02m4gm1fn7gnymrkbdxflgzxwl7m96aryv8wp3f3366l8j";