diff --git a/AFNetworking/AFHTTPRequestOperation.m b/AFNetworking/AFHTTPRequestOperation.m
index a842c95..6f052d5 100644
--- a/AFNetworking/AFHTTPRequestOperation.m
+++ b/AFNetworking/AFHTTPRequestOperation.m
@@ -44,6 +44,7 @@
 
 - (void)dealloc {
     [_acceptableStatusCodes release];
+    [_acceptableContentTypes release];
     [_HTTPError release];
     [super dealloc];
 }