diff --git a/doc/extensions/zephyr/link-roles.py b/doc/extensions/zephyr/link-roles.py
index ecb29398c4c..9b827e53565 100644
--- a/doc/extensions/zephyr/link-roles.py
+++ b/doc/extensions/zephyr/link-roles.py
@@ -14,7 +14,7 @@ from local_util import run_cmd_get_output
 def get_github_rev():
     tag = run_cmd_get_output('git describe --exact-match')
     if tag:
-        return tag
+        return tag.decode("utf-8")
     else:
         return 'master'