diff --git a/var/spack/repos/builtin/packages/gmake/package.py b/var/spack/repos/builtin/packages/gmake/package.py
index 40b566eabc9..c94d37973ad 100644
--- a/var/spack/repos/builtin/packages/gmake/package.py
+++ b/var/spack/repos/builtin/packages/gmake/package.py
@@ -102,4 +102,8 @@ def setup_dependent_package(self, module, dspec):
 
     @property
     def libs(self):
-        return []
+        return LibraryList([])
+
+    @property
+    def headers(self):
+        return HeaderList([])