diff --git a/AFNetworking/AFHTTPClient.m b/AFNetworking/AFHTTPClient.m
index 2ba4d23..dfdf4f9 100644
--- a/AFNetworking/AFHTTPClient.m
+++ b/AFNetworking/AFHTTPClient.m
@@ -235,9 +235,14 @@ NSArray * AFQueryStringPairsFromKeyAndValue(NSString *key, id value) {
 	self.defaultHeaders = [NSMutableDictionary dictionary];
 
     // Accept-Language HTTP Header; see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.4
-    NSString *preferredLanguageCodes = [[NSLocale preferredLanguages] componentsJoinedByString:@", "];
-    [self setDefaultHeader:@"Accept-Language" value:[NSString stringWithFormat:@"%@, en-us;q=0.8", preferredLanguageCodes]];
-
+    NSMutableArray *acceptLanguagesComponents = [NSMutableArray array];
+    [[NSLocale preferredLanguages] enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
+        float q = 1.0f - (idx * 0.1f);
+        [acceptLanguagesComponents addObject:[NSString stringWithFormat:@"%@;q=%0.1g", obj, q]];
+        *stop = q <= 0.5f;
+    }];
+    [self setDefaultHeader:@"Accept-Language" value:[acceptLanguagesComponents componentsJoinedByString:@", "]];
+    
 #if defined(__IPHONE_OS_VERSION_MIN_REQUIRED)
     // User-Agent Header; see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.43
     [self setDefaultHeader:@"User-Agent" value:[NSString stringWithFormat:@"%@/%@ (%@; iOS %@; Scale/%0.2f)", [[[NSBundle mainBundle] infoDictionary] objectForKey:(NSString *)kCFBundleExecutableKey] ?: [[[NSBundle mainBundle] infoDictionary] objectForKey:(NSString *)kCFBundleIdentifierKey], (__bridge id)CFBundleGetValueForInfoDictionaryKey(CFBundleGetMainBundle(), kCFBundleVersionKey) ?: [[[NSBundle mainBundle] infoDictionary] objectForKey:(NSString *)kCFBundleVersionKey], [[UIDevice currentDevice] model], [[UIDevice currentDevice] systemVersion], ([[UIScreen mainScreen] respondsToSelector:@selector(scale)] ? [[UIScreen mainScreen] scale] : 1.0f)]];