diff --git a/extensions/amazon-lambda-http/http-event-server/src/main/java/io/quarkus/amazon/lambda/runtime/MockHttpEventServer.java b/extensions/amazon-lambda-http/http-event-server/src/main/java/io/quarkus/amazon/lambda/runtime/MockHttpEventServer.java
index e7b438422ea0c..69fe6e67955fe 100644
--- a/extensions/amazon-lambda-http/http-event-server/src/main/java/io/quarkus/amazon/lambda/runtime/MockHttpEventServer.java
+++ b/extensions/amazon-lambda-http/http-event-server/src/main/java/io/quarkus/amazon/lambda/runtime/MockHttpEventServer.java
@@ -128,6 +128,11 @@ public void processResponse(RoutingContext ctx, RoutingContext pending, Buffer b
                         }
                     }
                 }
+                if (res.getCookies() != null) {
+                    for (String cookie : res.getCookies()) {
+                        response.headers().add("set-cookie", cookie);
+                    }
+                }
                 response.setStatusCode(res.getStatusCode());
                 String body = res.getBody();
                 if (body != null) {
diff --git a/extensions/amazon-lambda-http/runtime/src/main/java/io/quarkus/amazon/lambda/http/LambdaHttpHandler.java b/extensions/amazon-lambda-http/runtime/src/main/java/io/quarkus/amazon/lambda/http/LambdaHttpHandler.java
index c7c9b7f10920b..8b5c2654937cd 100644
--- a/extensions/amazon-lambda-http/runtime/src/main/java/io/quarkus/amazon/lambda/http/LambdaHttpHandler.java
+++ b/extensions/amazon-lambda-http/runtime/src/main/java/io/quarkus/amazon/lambda/http/LambdaHttpHandler.java
@@ -108,6 +108,11 @@ public void handleMessage(Object msg) {
                         if (allForName == null || allForName.isEmpty()) {
                             continue;
                         }
+                        // Handle cookies separately to preserve commas in the header values
+                        if ("set-cookie".equals(name)) {
+                            responseBuilder.setCookies(allForName);
+                            continue;
+                        }
                         final StringBuilder sb = new StringBuilder();
                         for (Iterator<String> valueIterator = allForName.iterator(); valueIterator.hasNext();) {
                             sb.append(valueIterator.next());