Index: src/OFArray.m
==================================================================
--- src/OFArray.m
+++ src/OFArray.m
@@ -163,11 +163,11 @@
 					count: count] autorelease];
 }
 
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFArray class]) {
+	if ([self isMemberOfClass: [OFArray class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 		} @catch (id e) {
 			[self release];
 			@throw e;

Index: src/OFBlock.m
==================================================================
--- src/OFBlock.m
+++ src/OFBlock.m
@@ -161,11 +161,11 @@
 void *
 _Block_copy(const void *block_)
 {
 	of_block_literal_t *block = (of_block_literal_t *)block_;
 
-	if (object_getClass((id)block) == (Class)&_NSConcreteStackBlock) {
+	if ([(id)block isMemberOfClass: (Class)&_NSConcreteStackBlock]) {
 		of_block_literal_t *copy;
 
 		if ((copy = malloc(block->descriptor->size)) == NULL) {
 			alloc_failed_exception.isa =
 			    [OFAllocFailedException class];
@@ -181,11 +181,11 @@
 			block->descriptor->copy_helper(copy, block);
 
 		return copy;
 	}
 
-	if (object_getClass((id)block) == (Class)&_NSConcreteMallocBlock) {
+	if ([(id)block isMemberOfClass: (Class)&_NSConcreteMallocBlock]) {
 #ifdef OF_HAVE_ATOMIC_OPS
 		of_atomic_int_inc(&block->flags);
 #else
 		unsigned hash = SPINLOCK_HASH(block);
 
@@ -464,11 +464,11 @@
 	OF_UNRECOGNIZED_SELECTOR
 }
 
 - (instancetype)retain
 {
-	if (object_getClass(self) == (Class)&_NSConcreteMallocBlock)
+	if ([self isMemberOfClass: (Class)&_NSConcreteMallocBlock])
 		return Block_copy(self);
 
 	return self;
 }
 
@@ -477,31 +477,31 @@
 	return Block_copy(self);
 }
 
 - (instancetype)autorelease
 {
-	if (object_getClass(self) == (Class)&_NSConcreteMallocBlock)
+	if ([self isMemberOfClass: (Class)&_NSConcreteMallocBlock])
 		return [super autorelease];
 
 	return self;
 }
 
 - (unsigned int)retainCount
 {
-	if (object_getClass(self) == (Class)&_NSConcreteMallocBlock)
+	if ([self isMemberOfClass: (Class)&_NSConcreteMallocBlock])
 		return ((of_block_literal_t *)self)->flags &
 		    OF_BLOCK_REFCOUNT_MASK;
 
 	return OF_RETAIN_COUNT_MAX;
 }
 
 - (void)release
 {
-	if (object_getClass(self) == (Class)&_NSConcreteMallocBlock)
+	if ([self isMemberOfClass: (Class)&_NSConcreteMallocBlock])
 		Block_release(self);
 }
 
 - (void)dealloc
 {
 	OF_DEALLOC_UNSUPPORTED
 }
 @end

Index: src/OFConstantString.m
==================================================================
--- src/OFConstantString.m
+++ src/OFConstantString.m
@@ -136,11 +136,11 @@
 - (void)finishInitialization
 {
 	@synchronized (self) {
 		struct of_string_utf8_ivars *ivars;
 
-		if (object_getClass(self) == [OFString_const class])
+		if ([self isMemberOfClass: [OFString_const class]])
 			return;
 
 		if ((ivars = calloc(1, sizeof(*ivars))) == NULL)
 			@throw [OFOutOfMemoryException
 			    exceptionWithRequestedSize: sizeof(*ivars)];

Index: src/OFCountedSet.m
==================================================================
--- src/OFCountedSet.m
+++ src/OFCountedSet.m
@@ -115,11 +115,11 @@
 	return [super alloc];
 }
 
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFCountedSet class]) {
+	if ([self isMemberOfClass: [OFCountedSet class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 		} @catch (id e) {
 			[self release];
 			@throw e;

Index: src/OFDictionary.m
==================================================================
--- src/OFDictionary.m
+++ src/OFDictionary.m
@@ -185,11 +185,11 @@
 	return ret;
 }
 
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFDictionary class]) {
+	if ([self isMemberOfClass: [OFDictionary class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 		} @catch (id e) {
 			[self release];
 			@throw e;

Index: src/OFEnumerator.m
==================================================================
--- src/OFEnumerator.m
+++ src/OFEnumerator.m
@@ -22,11 +22,11 @@
 #import "OFArray.h"
 
 @implementation OFEnumerator
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFEnumerator class]) {
+	if ([self isMemberOfClass: [OFEnumerator class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 			abort();
 		} @catch (id e) {
 			[self release];

Index: src/OFMutableArray.m
==================================================================
--- src/OFMutableArray.m
+++ src/OFMutableArray.m
@@ -231,11 +231,11 @@
 	return [[[self alloc] initWithCapacity: capacity] autorelease];
 }
 
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFMutableArray class]) {
+	if ([self isMemberOfClass: [OFMutableArray class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 			abort();
 		} @catch (id e) {
 			[self release];

Index: src/OFMutableDictionary.m
==================================================================
--- src/OFMutableDictionary.m
+++ src/OFMutableDictionary.m
@@ -140,11 +140,11 @@
 	return [[[self alloc] initWithCapacity: capacity] autorelease];
 }
 
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFMutableDictionary class]) {
+	if ([self isMemberOfClass: [OFMutableDictionary class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 		} @catch (id e) {
 			[self release];
 			@throw e;

Index: src/OFMutableSet.m
==================================================================
--- src/OFMutableSet.m
+++ src/OFMutableSet.m
@@ -124,11 +124,11 @@
 	return [[[self alloc] initWithCapacity: capacity] autorelease];
 }
 
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFMutableSet class]) {
+	if ([self isMemberOfClass: [OFMutableSet class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 			abort();
 		} @catch (id e) {
 			[self release];

Index: src/OFPlugin.m
==================================================================
--- src/OFPlugin.m
+++ src/OFPlugin.m
@@ -94,11 +94,11 @@
 	return plugin;
 }
 
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFPlugin class]) {
+	if ([self isMemberOfClass: [OFPlugin class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 		} @catch (id e) {
 			[self release];
 			@throw e;

Index: src/OFSeekableStream.m
==================================================================
--- src/OFSeekableStream.m
+++ src/OFSeekableStream.m
@@ -24,11 +24,11 @@
 #import "OFSeekableStream.h"
 
 @implementation OFSeekableStream
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFSeekableStream class]) {
+	if ([self isMemberOfClass: [OFSeekableStream class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 			abort();
 		} @catch (id e) {
 			[self release];

Index: src/OFSet.m
==================================================================
--- src/OFSet.m
+++ src/OFSet.m
@@ -150,11 +150,11 @@
 					count: count] autorelease];
 }
 
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFSet class]) {
+	if ([self isMemberOfClass: [OFSet class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 		} @catch (id e) {
 			[self release];
 			@throw e;

Index: src/OFStream.m
==================================================================
--- src/OFStream.m
+++ src/OFStream.m
@@ -67,11 +67,11 @@
 }
 #endif
 
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFStream class]) {
+	if ([self isMemberOfClass: [OFStream class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 			abort();
 		} @catch (id e) {
 			[self release];

Index: src/OFString.m
==================================================================
--- src/OFString.m
+++ src/OFString.m
@@ -828,11 +828,11 @@
 	return ret;
 }
 
 - (instancetype)init
 {
-	if (object_getClass(self) == [OFString class]) {
+	if ([self isMemberOfClass: [OFString class]]) {
 		@try {
 			[self doesNotRecognizeSelector: _cmd];
 		} @catch (id e) {
 			[self release];
 			@throw e;