diff --git a/core/src/main/java/org/jclouds/rest/internal/RestAnnotationProcessor.java b/core/src/main/java/org/jclouds/rest/internal/RestAnnotationProcessor.java
index 101d863ba0..e29dede0eb 100644
--- a/core/src/main/java/org/jclouds/rest/internal/RestAnnotationProcessor.java
+++ b/core/src/main/java/org/jclouds/rest/internal/RestAnnotationProcessor.java
@@ -1294,14 +1294,16 @@ public class RestAnnotationProcessor<T> {
          for (Annotation key : entry.getValue()) {
             Set<Annotation> extractors = indexToParamExtractor.get(entry.getKey());
             String paramKey = ((QueryParam) key).value();
-            String paramValue;
+            Object paramValue;
             if (extractors != null && extractors.size() > 0) {
                ParamParser extractor = (ParamParser) extractors.iterator().next();
                paramValue = injector.getInstance(extractor.value()).apply(args[entry.getKey()]);
             } else {
-               paramValue = args[entry.getKey()].toString();
+               paramValue = args[entry.getKey()];
+            }
+            if (paramValue != null) {
+                queryParamValues.put(paramKey, paramValue.toString());
             }
-            queryParamValues.put(paramKey, paramValue);
          }
       }