diff --git a/pkgs/os-specific/linux/pam_ldap/default.nix b/pkgs/os-specific/linux/pam_ldap/default.nix
index e7f2c8278e1a..5b34a8bc82b5 100644
--- a/pkgs/os-specific/linux/pam_ldap/default.nix
+++ b/pkgs/os-specific/linux/pam_ldap/default.nix
@@ -10,6 +10,7 @@ stdenv.mkDerivation rec {
 
   postPatch = ''
     patchShebangs ./vers_string
+    substituteInPlace vers_string --replace "cvslib.pl" "./cvslib.pl"
   '';
 
   preInstall = "