diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ApiMessageHttpRequestFormatter.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ApiMessageHttpRequestFormatter.java
index ee9794805..7aba4acd2 100644
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ApiMessageHttpRequestFormatter.java
+++ b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ApiMessageHttpRequestFormatter.java
@@ -75,6 +75,7 @@ ApiMessageHttpRequestFormatter.Builder<RequestT> newBuilder() {
     return new ApiMessageHttpRequestFormatter.Builder<>();
   }
 
+  @SuppressWarnings("unchecked")
   @Override
   public Map<String, List<String>> getQueryParamNames(RequestT apiMessage) {
     Set<String> paramNames = getQueryParamNames();
diff --git a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ApiMethodDescriptor.java b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ApiMethodDescriptor.java
index cdea41a94..a31110fd0 100644
--- a/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ApiMethodDescriptor.java
+++ b/gax-httpjson/src/main/java/com/google/api/gax/httpjson/ApiMethodDescriptor.java
@@ -50,7 +50,7 @@ public abstract class ApiMethodDescriptor<RequestT, ResponseT> {
   public abstract String getHttpMethod();
 
   public static <RequestT, ResponseT> Builder<RequestT, ResponseT> newBuilder() {
-    return new AutoValue_ApiMethodDescriptor.Builder();
+    return new AutoValue_ApiMethodDescriptor.Builder<RequestT, ResponseT>();
   }
 
   @AutoValue.Builder