diff --git a/moto/awslambda/models.py b/moto/awslambda/models.py
index b34e3e9d4..1c489f3fd 100644
--- a/moto/awslambda/models.py
+++ b/moto/awslambda/models.py
@@ -111,7 +111,7 @@ class LambdaFunction(BaseModel):
         }
 
     def get_code(self):
-        if 'S3Key' in self.code:
+        if isinstance(self.code, dict):
             return {
                 "Code": {
                     "Location": "s3://lambda-functions.aws.amazon.com/{0}".format(self.code['S3Key']),
diff --git a/tests/test_awslambda/test_lambda.py b/tests/test_awslambda/test_lambda.py
index b1de685b8..8a5d84f33 100644
--- a/tests/test_awslambda/test_lambda.py
+++ b/tests/test_awslambda/test_lambda.py
@@ -624,4 +624,4 @@ def test_get_function_created_with_zipfile():
                 "SubnetIds": [],
             }
         },
-    )
\ No newline at end of file
+    )