diff --git a/querydsl-core/src/main/java/com/mysema/query/support/NumberConversion.java b/querydsl-core/src/main/java/com/mysema/query/support/NumberConversion.java
index 9cbba2eaa..88df97738 100644
--- a/querydsl-core/src/main/java/com/mysema/query/support/NumberConversion.java
+++ b/querydsl-core/src/main/java/com/mysema/query/support/NumberConversion.java
@@ -53,7 +53,11 @@ public class NumberConversion<T> extends ExpressionBase<T> implements FactoryExp
 
     @Override
     public T newInstance(Object... args) {
-        return (T)MathUtils.cast((Number)args[0], (Class)getType());
+        if (args[0] != null) {
+            return (T)MathUtils.cast((Number)args[0], (Class)getType());    
+        } else {
+            return null;
+        }        
     }
 
 }
diff --git a/querydsl-jpa/src/test/java/com/mysema/query/AbstractStandardTest.java b/querydsl-jpa/src/test/java/com/mysema/query/AbstractStandardTest.java
index a58a132e2..12beff089 100644
--- a/querydsl-jpa/src/test/java/com/mysema/query/AbstractStandardTest.java
+++ b/querydsl-jpa/src/test/java/com/mysema/query/AbstractStandardTest.java
@@ -975,6 +975,20 @@ public abstract class AbstractStandardTest {
         query().from(cat).uniqueResult(cat.bodyWeight.sum().negate());
     }
     
+    @Test
+    public void Sum_NoRows_Double() {
+        query().from(cat)
+            .where(cat.name.eq(UUID.randomUUID().toString()))
+            .uniqueResult(cat.bodyWeight.sum());
+    }
+    
+    @Test
+    public void Sum_NoRows_Float() {
+        query().from(cat)
+            .where(cat.name.eq(UUID.randomUUID().toString()))
+            .uniqueResult(cat.floatProperty.sum());
+    }
+    
     @Test
     public void Sum_as_Float() {
         float val = query().from(cat).uniqueResult(cat.floatProperty.sum());