diff --git a/AFNetworking/AFHTTPRequestOperation.m b/AFNetworking/AFHTTPRequestOperation.m
index d6ba4a310e..5fca1eb90f 100644
--- a/AFNetworking/AFHTTPRequestOperation.m
+++ b/AFNetworking/AFHTTPRequestOperation.m
@@ -188,7 +188,7 @@ - (void)pause {
 }
 
 - (BOOL)hasAcceptableStatusCode {
-    return ![[self class] acceptableStatusCodes] || [[[self class] acceptableStatusCodes] containsIndex:[self.response statusCode]];
+    return ![[self class] acceptableStatusCodes] || [[[self class] acceptableStatusCodes] containsIndex:(NSUInteger)[self.response statusCode]];
 }
 
 - (BOOL)hasAcceptableContentType {