diff --git a/src/event-sources/utils.js b/src/event-sources/utils.js
index 5db4ecbd..46c99b5a 100644
--- a/src/event-sources/utils.js
+++ b/src/event-sources/utils.js
@@ -32,7 +32,7 @@ function getRequestValuesFromEvent ({
 
   if (event.multiValueHeaders) {
     headers = getCommaDelimitedHeaders({ headersMap: event.multiValueHeaders, lowerCaseKey: true })
-  } else {
+  } else if (event.headers) {
     headers = event.headers
   }