@@ -109,21 +109,22 @@
 {
 }
 
 - (void)dealloc
 {
-	@throw [OFNotImplementedException exceptionWithClass: isa
+	@throw [OFNotImplementedException exceptionWithClass: [self class]
 						    selector: _cmd];
 	[super dealloc];	/* Get rid of a stupid warning */
 }
 @end
 
 @implementation OFDictionary
 + (void)initialize
 {
 	if (self == [OFDictionary class])
-		placeholder.isa = [OFDictionary_placeholder class];
+		object_setClass((id)&placeholder,
+		    [OFDictionary_placeholder class]);
 }
 
 + alloc
 {
 	if (self == [OFDictionary class])
@@ -178,12 +179,12 @@
 	return ret;
 }
 
 - init
 {
-	if (isa == [OFDictionary class]) {
-		Class c = isa;
+	if (object_getClass(self) == [OFDictionary class]) {
+		Class c = [self class];
 		[self release];
 		@throw [OFNotImplementedException exceptionWithClass: c
 							    selector: _cmd];
 	}
 
@@ -190,11 +191,11 @@
 	return [super init];
 }
 
 - initWithDictionary: (OFDictionary*)dictionary
 {
-	Class c = isa;
+	Class c = [self class];
 	[self release];
 	@throw [OFNotImplementedException exceptionWithClass: c
 						    selector: _cmd];
 }
 
@@ -205,21 +206,21 @@
 }
 
 - initWithObjects: (OFArray*)objects
 	  forKeys: (OFArray*)keys
 {
-	Class c = isa;
+	Class c = [self class];
 	[self release];
 	@throw [OFNotImplementedException exceptionWithClass: c
 						    selector: _cmd];
 }
 
 - initWithObjects: (id const*)objects
 	  forKeys: (id const*)keys
 	    count: (size_t)count
 {
-	Class c = isa;
+	Class c = [self class];
 	[self release];
 	@throw [OFNotImplementedException exceptionWithClass: c
 						    selector: _cmd];
 }
 
@@ -237,27 +238,27 @@
 }
 
 - initWithKey: (id)firstKey
     arguments: (va_list)arguments
 {
-	Class c = isa;
+	Class c = [self class];
 	[self release];
 	@throw [OFNotImplementedException exceptionWithClass: c
 						    selector: _cmd];
 }
 
 - initWithSerialization: (OFXMLElement*)element
 {
-	Class c = isa;
+	Class c = [self class];
 	[self release];
 	@throw [OFNotImplementedException exceptionWithClass: c
 						    selector: _cmd];
 }
 
 - (id)objectForKey: (id)key
 {
-	@throw [OFNotImplementedException exceptionWithClass: isa
+	@throw [OFNotImplementedException exceptionWithClass: [self class]
 						    selector: _cmd];
 }
 
 - (id)objectForKeyedSubscript: (id)key
 {
@@ -264,11 +265,11 @@
 	return [self objectForKey: key];
 }
 
 - (size_t)count
 {
-	@throw [OFNotImplementedException exceptionWithClass: isa
+	@throw [OFNotImplementedException exceptionWithClass: [self class]
 						    selector: _cmd];
 }
 
 - copy
 {
@@ -409,25 +410,25 @@
 	return ret;
 }
 
 - (OFEnumerator*)objectEnumerator
 {
-	@throw [OFNotImplementedException exceptionWithClass: isa
+	@throw [OFNotImplementedException exceptionWithClass: [self class]
 						    selector: _cmd];
 }
 
 - (OFEnumerator*)keyEnumerator
 {
-	@throw [OFNotImplementedException exceptionWithClass: isa
+	@throw [OFNotImplementedException exceptionWithClass: [self class]
 						    selector: _cmd];
 }
 
 - (int)countByEnumeratingWithState: (of_fast_enumeration_state_t*)state
 			   objects: (id*)objects
 			     count: (int)count_
 {
-	@throw [OFNotImplementedException exceptionWithClass: isa
+	@throw [OFNotImplementedException exceptionWithClass: [self class]
 						    selector: _cmd];
 }
 
 #if defined(OF_HAVE_BLOCKS) && defined(OF_HAVE_FAST_ENUMERATION)
 - (void)enumerateKeysAndObjectsUsingBlock: