diff --git a/pkgs/development/libraries/openldap/default.nix b/pkgs/development/libraries/openldap/default.nix
index a4274f064e5..56955b88ee4 100644
--- a/pkgs/development/libraries/openldap/default.nix
+++ b/pkgs/development/libraries/openldap/default.nix
@@ -40,8 +40,8 @@ stdenv.mkDerivation rec {
     ++ stdenv.lib.optional stdenv.isFreeBSD "--with-pic";
 
   postBuild = ''
-    make $makeFlags -C contrib/slapd-modules/passwd/sha2
-    make $makeFlags -C contrib/slapd-modules/passwd/pbkdf2
+    make $makeFlags CC=$CC -C contrib/slapd-modules/passwd/sha2
+    make $makeFlags CC=$CC -C contrib/slapd-modules/passwd/pbkdf2
   '';
 
   doCheck = false; # needs a running LDAP server