diff --git a/lib/ansible/template/__init__.py b/lib/ansible/template/__init__.py
index cda58527f74..062c4d6889b 100644
--- a/lib/ansible/template/__init__.py
+++ b/lib/ansible/template/__init__.py
@@ -506,8 +506,8 @@ class Templar:
         are being changed.
         '''
 
-        if not isinstance(variables, dict):
-            raise AnsibleAssertionError("the type of 'variables' should be a dict but was a %s" % (type(variables)))
+        if not isinstance(variables, Mapping):
+            raise AnsibleAssertionError("the type of 'variables' should be a Mapping but was a %s" % (type(variables)))
         self._available_variables = variables
         self._cached_result = {}