diff --git a/course/content.py b/course/content.py
index fbf2c25d368985c1be5419b7162b50c2231d64b7..2e0f65b9a6a67e2cdf5e3813f37f718d745a2928 100644
--- a/course/content.py
+++ b/course/content.py
@@ -66,6 +66,19 @@ class SubdirRepoWrapper(object):
         self.repo.close()
 
 
+def get_true_repo_and_path(repo, path):
+    if isinstance(repo, SubdirRepoWrapper):
+        if path:
+            path = repo.subdir + "/" + path
+        else:
+            path = repo.subdir
+
+        return repo.repo, path
+
+    else:
+        return repo, path
+
+
 def get_course_repo_path(course):
     from os.path import join
     return join(settings.GIT_ROOT, course.identifier)
@@ -88,13 +101,7 @@ def get_repo_blob(repo, full_name, commit_sha, allow_tree=True):
     :arg allow_tree: Allow the resulting object to be a directory
     """
 
-    if isinstance(repo, SubdirRepoWrapper):
-        if full_name:
-            full_name = repo.subdir + "/" + full_name
-        else:
-            full_name = repo.subdir
-
-        repo = repo.repo
+    repo, full_name = get_true_repo_and_path(repo, full_name)
 
     names = full_name.split("/")
 
diff --git a/course/validation.py b/course/validation.py
index 7aadb27bd6b44b32b512ff508c300cf4bd310224..376aa068ca810b5dc4946649d65bfb6acd4ad75c 100644
--- a/course/validation.py
+++ b/course/validation.py
@@ -1024,6 +1024,9 @@ def check_attributes_yml(vctx, repo, path, tree):
             - test2.pdf
             - 42
     """
+    from course.content import get_true_repo_and_path
+    repo, path = get_true_repo_and_path(repo, path)
+
     try:
         dummy, attr_blob_sha = tree[b".attributes.yml"]
     except KeyError: