diff --git a/AFNetworking/AFHTTPRequestOperation.m b/AFNetworking/AFHTTPRequestOperation.m
index b229fb7..c1bff7d 100644
--- a/AFNetworking/AFHTTPRequestOperation.m
+++ b/AFNetworking/AFHTTPRequestOperation.m
@@ -72,7 +72,6 @@ static NSString * AFStringFromIndexSet(NSIndexSet *indexSet) {
     }
     
     self.acceptableStatusCodes = [NSIndexSet indexSetWithIndexesInRange:NSMakeRange(200, 100)];
-    self.completionBlock = NULL;
     
     return self;
 }