diff --git a/pkgs/development/beam-modules/build-erlang-mk.nix b/pkgs/development/beam-modules/build-erlang-mk.nix
index 4ea8a52601c..c2d1ebabae2 100644
--- a/pkgs/development/beam-modules/build-erlang-mk.nix
+++ b/pkgs/development/beam-modules/build-erlang-mk.nix
@@ -40,7 +40,7 @@ let
     ''
     else setupHook;
 
-    buildInputs = [ erlang perl which gitMinimal wget ];
+    buildInputs = buildInputs ++ [ erlang perl which gitMinimal wget ];
     propagatedBuildInputs = beamDeps;
 
     buildFlags = [ "SKIP_DEPS=1" ]