Index: src/OFArray.m
==================================================================
--- src/OFArray.m
+++ src/OFArray.m
@@ -540,20 +540,26 @@
 {
 	return [[[OFArrayEnumerator alloc] initWithArray: self
 					    mutationsPtr: NULL] autorelease];
 }
 
-#ifdef OF_HAVE_BLOCKS
+#if defined(OF_HAVE_BLOCKS) && defined(OF_HAVE_FAST_ENUMERATION)
 - (void)enumerateObjectsUsingBlock: (of_array_enumeration_block_t)block
 {
-	size_t i, count = [self count];
+	size_t i = 0;
 	BOOL stop = NO;
 
-	for (i = 0; i < count && !stop; i++)
-		block([self objectAtIndex: i], i, &stop);
+	for (id object in self) {
+		block(object, i++, &stop);
+
+		if (stop)
+			break;
+	}
 }
+#endif
 
+#ifdef OF_HAVE_BLOCKS
 - (OFArray*)mappedArrayUsingBlock: (of_array_map_block_t)block
 {
 	OFArray *ret;
 	size_t count = [self count];
 	id *tmp = [self allocMemoryForNItems: count

Index: src/OFDictionary.m
==================================================================
--- src/OFDictionary.m
+++ src/OFDictionary.m
@@ -385,25 +385,26 @@
 {
 	@throw [OFNotImplementedException newWithClass: isa
 					      selector: _cmd];
 }
 
-#ifdef OF_HAVE_BLOCKS
+#if defined(OF_HAVE_BLOCKS) && defined(OF_HAVE_FAST_ENUMERATION)
 - (void)enumerateKeysAndObjectsUsingBlock:
     (of_dictionary_enumeration_block_t)block
 {
-	OFAutoreleasePool *pool = [[OFAutoreleasePool alloc] init];
-	OFEnumerator *enumerator = [self keyEnumerator];
-	id key;
 	BOOL stop = NO;
 
-	while (!stop && (key = [enumerator nextObject]) != nil)
+	for (id key in self) {
 		block(key, [self objectForKey: key], &stop);
 
-	[pool release];
+		if (stop)
+			break;
+	}
 }
+#endif
 
+#ifdef OF_HAVE_BLOCKS
 - (OFDictionary*)mappedDictionaryUsingBlock: (of_dictionary_map_block_t)block
 {
 	OFMutableDictionary *new = [OFMutableDictionary dictionary];
 
 	[self enumerateKeysAndObjectsUsingBlock: ^ (id key, id object,

Index: src/OFSet.m
==================================================================
--- src/OFSet.m
+++ src/OFSet.m
@@ -360,24 +360,25 @@
 	[element autorelease];
 
 	return element;
 }
 
-#ifdef OF_HAVE_BLOCKS
+#if defined(OF_HAVE_BLOCKS) && defined(OF_HAVE_FAST_ENUMERATION)
 - (void)enumerateObjectsUsingBlock: (of_set_enumeration_block_t)block
 {
-	OFAutoreleasePool *pool = [[OFAutoreleasePool alloc] init];
-	OFEnumerator *enumerator = [self objectEnumerator];
-	id object;
 	BOOL stop = NO;
 
-	while (!stop && (object = [enumerator nextObject]) != nil)
+	for (id object in self) {
 		block(object, &stop);
 
-	[pool release];
+		if (stop)
+			break;
+	}
 }
+#endif
 
+#ifdef OF_HAVE_BLOCKS
 - (OFSet*)filteredSetUsingBlock: (of_set_filter_block_t)block
 {
 	OFMutableSet *ret = [OFMutableSet set];
 
 	[self enumerateObjectsUsingBlock: ^ (id object, BOOL *stop) {