diff --git a/nikola/utils.py b/nikola/utils.py
index e8efba290..e568222fb 100644
--- a/nikola/utils.py
+++ b/nikola/utils.py
@@ -576,7 +576,7 @@ def __repr__(self):
                                                            sort_keys=True))
 
 
-def pkg_resources(package, resource):
+def pkg_resources(package: str, resource: str) -> str:
     """Return the resource based on the python version."""
     if sys.version_info.minor <= 8:
         return str(resources.path(package, resource))