diff --git a/AFNetworking/AFHTTPClient.m b/AFNetworking/AFHTTPClient.m
index bf26305..b9736e2 100644
--- a/AFNetworking/AFHTTPClient.m
+++ b/AFNetworking/AFHTTPClient.m
@@ -146,10 +146,11 @@ NSArray * AFQueryStringPairsFromKeyAndValue(NSString *key, id value) {
     NSMutableArray *mutableQueryStringComponents = [NSMutableArray array];
 
     if ([value isKindOfClass:[NSDictionary class]]) {
+        NSDictionary *dictionary = value;
         // Sort dictionary keys to ensure consistent ordering in query string, which is important when deserializing potentially ambiguous sequences, such as an array of dictionaries
         NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"description" ascending:YES selector:@selector(caseInsensitiveCompare:)];
-        [[[value allKeys] sortedArrayUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]] enumerateObjectsUsingBlock:^(id nestedKey, __unused NSUInteger idx, __unused BOOL *stop) {
-            id nestedValue = [value objectForKey:nestedKey];
+        [[[dictionary allKeys] sortedArrayUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]] enumerateObjectsUsingBlock:^(id nestedKey, __unused NSUInteger idx, __unused BOOL *stop) {
+            id nestedValue = [dictionary objectForKey:nestedKey];
             if (nestedValue) {
                 [mutableQueryStringComponents addObjectsFromArray:AFQueryStringPairsFromKeyAndValue((key ? [NSString stringWithFormat:@"%@[%@]", key, nestedKey] : nestedKey), nestedValue)];
             }