diff --git a/salt/hg/files/hg/src/app.py b/salt/hg/files/hg/src/app.py
index c261caf3..1cd86e1e 100644
--- a/salt/hg/files/hg/src/app.py
+++ b/salt/hg/files/hg/src/app.py
@@ -73,4 +73,6 @@ def hgrev(repo, rev):
         response.headers["Content-Type"] = "text/plain"
         return response
 
-    return make_response(result.stdout, 200)
+    response = make_response(result.stdout, 200)
+    response.headers["Content-Type"] = "text/plain"
+    return response