diff --git a/pkgs/development/python-modules/shapely/default.nix b/pkgs/development/python-modules/shapely/default.nix
index 48d4fa68f65..8f81a810cfa 100644
--- a/pkgs/development/python-modules/shapely/default.nix
+++ b/pkgs/development/python-modules/shapely/default.nix
@@ -27,7 +27,7 @@ buildPythonPackage rec {
     libc = if stdenv.isDarwin then "libc.dylib" else "libc.so.6";
   in ''
     sed -i "s|_lgeos = load_dll('geos_c', fallbacks=.*)|_lgeos = load_dll('geos_c', fallbacks=['${geos}/lib/libgeos_c${stdenv.hostPlatform.extensions.sharedLibrary}'])|" shapely/geos.py
-    sed -i "s|free = load_dll('c').free|free = load_dll('c', fallbacks=['${stdenv.cc.libc}/lib/${stdenv.cc.libc}']).free|" shapely/geos.py
+    sed -i "s|free = load_dll('c').free|free = load_dll('c', fallbacks=['${stdenv.cc.libc}/lib/${libc}']).free|" shapely/geos.py
   '';
 
   # tests/test_voctorized fails because the vectorized extension is not