diff --git a/CHANGELOG.md b/CHANGELOG.md
index e534780..1daade2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## v1.5.6
+
+- All response header keys are converted to lowercase (iOS only)
+
 ## v1.5.5
 
 - added a function to remove all cookies for a URL
diff --git a/package.json b/package.json
index 251eeb2..e945197 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "cordova-plugin-advanced-http",
-  "version": "1.5.5",
+  "version": "1.5.6",
   "description": "Cordova / Phonegap plugin for communicating with HTTP servers using SSL pinning",
   "scripts": {
     "build": "cp node_modules/umd-tough-cookie/lib/umd-tough-cookie.js www/umd-tough-cookie.js",
diff --git a/plugin.xml b/plugin.xml
index c36db0d..61bdd16 100644
--- a/plugin.xml
+++ b/plugin.xml
@@ -2,7 +2,7 @@
 <plugin xmlns="http://www.phonegap.com/ns/plugins/1.0"
   xmlns:android="http://schemas.android.com/apk/res/android"
   id="cordova-plugin-advanced-http"
-  version="1.5.5">
+  version="1.5.6">
 
     <name>Advanced HTTP plugin</name>
 
diff --git a/src/ios/CordovaHttpPlugin.m b/src/ios/CordovaHttpPlugin.m
index 460afd0..17d7fa5 100644
--- a/src/ios/CordovaHttpPlugin.m
+++ b/src/ios/CordovaHttpPlugin.m
@@ -7,6 +7,7 @@
 
 - (void)setRequestHeaders:(NSDictionary*)headers forManager:(AFHTTPSessionManager*)manager;
 - (void)setResults:(NSMutableDictionary*)dictionary withTask:(NSURLSessionTask*)task;
+- (NSMutableDictionary*)copyHeaderFields:(NSDictionary*)headerFields;
 
 @end
 
@@ -37,10 +38,22 @@
     if (task.response != nil) {
         NSHTTPURLResponse *response = (NSHTTPURLResponse *)task.response;
         [dictionary setObject:[NSNumber numberWithInt:response.statusCode] forKey:@"status"];
-        [dictionary setObject:response.allHeaderFields forKey:@"headers"];
+        [dictionary setObject:[self copyHeaderFields:response.allHeaderFields] forKey:@"headers"];
     }
 }
 
+- (NSMutableDictionary*)copyHeaderFields:(NSDictionary *)headerFields {
+	NSMutableDictionary *headerFieldsCopy = [[NSMutableDictionary alloc] initWithCapacity:headerFields.count];
+	NSString *headerKeyCopy;
+
+	for (NSString *headerKey in headerFields.allKeys) {
+		headerKeyCopy = [[headerKey mutableCopy] lowercaseString];
+		[headerFieldsCopy setValue:[headerFields objectForKey:headerKey] forKey:headerKeyCopy];
+	}
+
+	return headerFieldsCopy;
+}
+
 - (void)enableSSLPinning:(CDVInvokedUrlCommand*)command {
     bool enable = [[command.arguments objectAtIndex:0] boolValue];
     if (enable) {