diff --git a/pkgs/os-specific/linux/drbd/utils.nix b/pkgs/os-specific/linux/drbd/utils.nix
index 7d16146e4244..e547c659afb8 100644
--- a/pkgs/os-specific/linux/drbd/utils.nix
+++ b/pkgs/os-specific/linux/drbd/utils.nix
@@ -42,14 +42,16 @@ stdenv.mkDerivation rec {
     keyutils
     udevCheckHook
     gettext
+    perl
+    perlPackages.Po4a
   ];
 
   buildInputs = [
-    perl
-    perlPackages.Po4a
     gettext
   ];
 
+  strictDeps = true;
+
   configureFlags = [
     "--libdir=${placeholder "out"}/lib"
     "--sbindir=${placeholder "out"}/bin"