diff --git a/src/taskgraph/util/hash.py b/src/taskgraph/util/hash.py
index 5d884fc31..26de8e526 100644
--- a/src/taskgraph/util/hash.py
+++ b/src/taskgraph/util/hash.py
@@ -55,4 +55,4 @@ def _find_matching_files(base_path, pattern):
 
 @memoize
 def _get_all_files(base_path):
-    return [str(path) for path in Path(base_path).rglob("*") if path.is_file()]
+    return [mozpath.normsep(str(path)) for path in Path(base_path).rglob("*") if path.is_file()]