diff --git a/Source/NSNumber.m b/Source/NSNumber.m
index 7a4e69711..1cb73cb07 100644
--- a/Source/NSNumber.m
+++ b/Source/NSNumber.m
@@ -763,6 +763,10 @@ if (aValue >= -1 && aValue <= 12)\
  */
 - (id) init
 {
+  if (object_getClass(self) != NSNumberClass)
+    {
+      return [super init];
+    }
   DESTROY(self);
   return nil;
 }