diff --git a/awx/api/serializers.py b/awx/api/serializers.py
index 98090bb611..a95a7f0c41 100644
--- a/awx/api/serializers.py
+++ b/awx/api/serializers.py
@@ -2763,8 +2763,8 @@ class AdHocCommandSerializer(UnifiedJobSerializer):
         redacted_extra_vars, removed_vars = extract_ansible_vars(value)
         if removed_vars:
             raise serializers.ValidationError(_(
-                "Variables {} are prohibited from use in ad hoc commands."
-            ).format(",".join(removed_vars)))
+                "{} are prohibited from use in ad hoc commands."
+            ).format(", ".join(removed_vars)))
         return vars_validate_or_raise(value)
 
 
diff --git a/awx/main/tasks.py b/awx/main/tasks.py
index 3bc4bc9c45..66ba251f40 100644
--- a/awx/main/tasks.py
+++ b/awx/main/tasks.py
@@ -2142,8 +2142,8 @@ class RunAdHocCommand(BaseTask):
             redacted_extra_vars, removed_vars = extract_ansible_vars(ad_hoc_command.extra_vars_dict)
             if removed_vars:
                 raise ValueError(_(
-                    "unable to use {} variables with ad hoc commands"
-                ).format(",".format(removed_vars)))
+                    "{} are prohibited from use in ad hoc commands."
+                ).format(", ".join(removed_vars)))
 
             args.extend(['-e', json.dumps(ad_hoc_command.extra_vars_dict)])