diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index 6cd2c4cb61b1..a5ba0d99600c 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -675,7 +675,7 @@ let pythonPackages = python.modules // rec {
     configureFlags = "--with-python=${python}";
 
     postConfigure = let
-      changeIconv = "-e s:^iconv_includes.*:iconv_includes=r'${pkgs.libxml2.libiconv}':";
+      changeIconv = ''-e "s:^iconv_includes.*:iconv_includes=r'${pkgs.libxml2.libiconv}':"'';
     in
       ''
         cd python