diff --git a/aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/model/AwsProxyRequest.java b/aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/model/AwsProxyRequest.java
index 53ad758f1..eeaaf4a6f 100644
--- a/aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/model/AwsProxyRequest.java
+++ b/aws-serverless-java-container-core/src/main/java/com/amazonaws/serverless/proxy/model/AwsProxyRequest.java
@@ -66,7 +66,7 @@ public String getQueryString() {
             for (String val : this.getMultiValueQueryStringParameters().get(key)) {
                 String separator = params.length() == 0 ? "?" : "&";
 
-                params.append(separator + key + "=" + val);
+                params.append(separator).append(key).append("=").append(val);
             }
         }