diff --git a/.gitignore b/.gitignore
index 2d3e279..8fac116 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,3 +19,4 @@ ObjXMPP.xcodeproj/*.pbxuser
 ObjXMPP.xcodeproj/project.xcworkspace
 ObjXMPP.xcodeproj/xcuserdata
 tests/tests
+tests/storage.binarypack
diff --git a/src/Makefile b/src/Makefile
index 0266634..23c2ed6 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -14,7 +14,7 @@ SRCS = XMPPAuthenticator.m	\
        XMPPEXTERNALAuth.m	\
        XMPPIQ.m			\
        XMPPJID.m		\
-       XMPPJSONFileStorage.m	\
+       XMPPFileStorage.m	\
        XMPPMessage.m		\
        XMPPMulticastDelegate.m	\
        XMPPPLAINAuth.m		\
diff --git a/src/XMPPJSONFileStorage.h b/src/XMPPFileStorage.h
similarity index 95%
rename from src/XMPPJSONFileStorage.h
rename to src/XMPPFileStorage.h
index d96d7d6..aecb682 100644
--- a/src/XMPPJSONFileStorage.h
+++ b/src/XMPPFileStorage.h
@@ -26,7 +26,7 @@
 
 @class OFMutableDictionary;
 
-@interface XMPPJSONFileStorage: OFObject <XMPPStorage>
+@interface XMPPFileStorage: OFObject <XMPPStorage>
 {
 	OFString *_file;
 	OFMutableDictionary *_data;
diff --git a/src/XMPPJSONFileStorage.m b/src/XMPPFileStorage.m
similarity index 94%
rename from src/XMPPJSONFileStorage.m
rename to src/XMPPFileStorage.m
index ffde40b..bf9a03c 100644
--- a/src/XMPPJSONFileStorage.m
+++ b/src/XMPPFileStorage.m
@@ -28,13 +28,14 @@
 #import <ObjFW/OFArray.h>
 #import <ObjFW/OFDictionary.h>
 #import <ObjFW/OFNumber.h>
+#import <ObjFW/OFDataArray.h>
 #import <ObjFW/OFAutoreleasePool.h>
 
 #import <ObjFW/OFNotImplementedException.h>
 
-#import "XMPPJSONFileStorage.h"
+#import "XMPPFileStorage.h"
 
-@implementation XMPPJSONFileStorage
+@implementation XMPPFileStorage
 - init
 {
 	Class c = [self class];
@@ -43,17 +44,17 @@
 						    selector: _cmd];
 }
 
-- initWithFile: (OFString*)file_
+- initWithFile: (OFString*)file
 {
 	self = [super init];
 
 	@try {
 		OFAutoreleasePool *pool = [OFAutoreleasePool new];
 
-		_file = [file_ copy];
+		_file = [file copy];
 		@try {
-			_data = [[[OFString stringWithContentsOfFile:
-			    _file] JSONValue] retain];
+			_data = [[[OFDataArray dataArrayWithContentsOfFile:
+			    file] binaryPackValue] retain];
 		} @catch (id e) {
 			_data = [OFMutableDictionary new];
 		}
@@ -77,7 +78,7 @@
 
 - (void)save
 {
-	[[_data JSONRepresentation] writeToFile: _file];
+	[[_data binaryPackRepresentation] writeToFile: _file];
 }
 
 - (void)XMPP_setObject: (id)object
diff --git a/src/XMPPRoster.m b/src/XMPPRoster.m
index 2bc979b..a1d882a 100644
--- a/src/XMPPRoster.m
+++ b/src/XMPPRoster.m
@@ -305,17 +305,17 @@
 	return rosterItem;
 }
 
-- (void)XMPP_handleInitialRosterForConnection: (XMPPConnection*)connection_
-					   IQ: (XMPPIQ*)iq
+- (void)XMPP_handleInitialRosterForConnection: (XMPPConnection*)connection
+					   IQ: (XMPPIQ*)IQ
 {
 	OFXMLElement *rosterElement;
 	OFEnumerator *enumerator;
 	OFXMLElement *element;
 
-	rosterElement = [iq elementForName: @"query"
+	rosterElement = [IQ elementForName: @"query"
 				 namespace: XMPP_NS_ROSTER];
 
-	if ([_connection supportsRosterVersioning]) {
+	if ([connection supportsRosterVersioning]) {
 		if (rosterElement == nil) {
 			OFDictionary *items = [_dataStorage
 			    dictionaryForPath: @"roster.items"];
@@ -361,7 +361,7 @@
 		[pool release];
 	}
 
-	if ([_connection supportsRosterVersioning] && rosterElement != nil) {
+	if ([connection supportsRosterVersioning] && rosterElement != nil) {
 		OFString *ver =
 		    [[rosterElement attributeForName: @"ver"] stringValue];
 		[_dataStorage setStringValue: ver
diff --git a/tests/test.m b/tests/test.m
index 9a31d84..46d2319 100644
--- a/tests/test.m
+++ b/tests/test.m
@@ -33,7 +33,7 @@
 #import "XMPPPresence.h"
 #import "XMPPRoster.h"
 #import "XMPPStreamManagement.h"
-#import "XMPPJSONFileStorage.h"
+#import "XMPPFileStorage.h"
 
 @interface AppDelegate: OFObject
 #ifdef OF_HAVE_OPTIONAL_PROTOCOLS
@@ -107,8 +107,8 @@ OF_APPLICATION_DELEGATE(AppDelegate)
 	conn = [[XMPPConnection alloc] init];
 	[conn addDelegate: self];
 
-	XMPPJSONFileStorage *storage =
-	    [[XMPPJSONFileStorage alloc] initWithFile: @"storage.json"];
+	XMPPFileStorage *storage =
+	    [[XMPPFileStorage alloc] initWithFile: @"storage.binarypack"];
 	[conn setDataStorage: storage];
 
 	roster = [[XMPPRoster alloc] initWithConnection: conn];