diff --git a/troposphere/serverless.py b/troposphere/serverless.py
index 4a6775280..485c5a3e5 100644
--- a/troposphere/serverless.py
+++ b/troposphere/serverless.py
@@ -770,7 +770,7 @@ class MQEvent(AWSObject):
         "MaximumBatchingWindowInSeconds": (integer, False),
         "Queues": ([str], True),
         "SecretsManagerKmsKeyId": (str, False),
-        "SourceAccessConfigurations": ([str], True),
+        "SourceAccessConfigurations": ([SourceAccessConfiguration], True),
     }