Index: src/Makefile
==================================================================
--- src/Makefile
+++ src/Makefile
@@ -205,10 +205,11 @@
 	OFRectValue.m			\
 	OFSandbox.m			\
 	OFSizeValue.m			\
 	OFStrPTime.m			\
 	OFSubarray.m			\
+	OFSubdata.m			\
 	OFUTF8String.m			\
 	${LIBBASES_M}			\
 	${RUNTIME_AUTORELEASE_M}	\
 	${RUNTIME_INSTANCE_M}		\
 	${UNICODE_M}

Index: src/OFAdjacentArray.m
==================================================================
--- src/OFAdjacentArray.m
+++ src/OFAdjacentArray.m
@@ -231,11 +231,12 @@
 	if ([self isKindOfClass: [OFMutableArray class]])
 		return [OFArray
 		    arrayWithObjects: (id *)_array.items + range.location
 			       count: range.length];
 
-	return [OFAdjacentSubarray arrayWithArray: self range: range];
+	return [[[OFAdjacentSubarray alloc] initWithArray: self
+						    range: range] autorelease];
 }
 
 - (bool)isEqual: (id)object
 {
 	OFArray *otherArray;

Index: src/OFAdjacentData.h
==================================================================
--- src/OFAdjacentData.h
+++ src/OFAdjacentData.h
@@ -20,10 +20,9 @@
 @interface OFAdjacentData: OFData
 {
 	unsigned char *_Nullable _items;
 	size_t _capacity, _count, _itemSize;
 	bool _freeWhenDone;
-	OFData *_Nullable _parentData;
 }
 @end
 
 OF_ASSUME_NONNULL_END

Index: src/OFAdjacentData.m
==================================================================
--- src/OFAdjacentData.m
+++ src/OFAdjacentData.m
@@ -96,12 +96,10 @@
 - (void)dealloc
 {
 	if (_freeWhenDone)
 		OFFreeMemory(_items);
 
-	[_parentData release];
-
 	[super dealloc];
 }
 
 - (size_t)count
 {
@@ -115,24 +113,6 @@
 
 - (const void *)items
 {
 	return _items;
 }
-
-- (OFData *)subdataWithRange: (OFRange)range
-{
-	OFAdjacentData *ret;
-
-	if (range.length > SIZE_MAX - range.location ||
-	    range.location + range.length > _count)
-		@throw [OFOutOfRangeException exception];
-
-	ret = [OFAdjacentData
-	    dataWithItemsNoCopy: _items + (range.location * _itemSize)
-			  count: range.length
-		       itemSize: _itemSize
-		   freeWhenDone: false];
-	ret->_parentData = [(_parentData != nil ? _parentData : self) copy];
-
-	return ret;
-}
 @end

Index: src/OFArray.m
==================================================================
--- src/OFArray.m
+++ src/OFArray.m
@@ -363,11 +363,12 @@
 	if (range.length > SIZE_MAX - range.location ||
 	    range.location + range.length < self.count)
 		@throw [OFOutOfRangeException exception];
 
 	if (![self isKindOfClass: [OFMutableArray class]])
-		return [OFSubarray arrayWithArray: self range: range];
+		return [[[OFSubarray alloc] initWithArray: self
+						    range: range] autorelease];
 
 	buffer = OFAllocMemory(range.length, sizeof(*buffer));
 	@try {
 		[self getObjects: buffer inRange: range];
 

Index: src/OFData.m
==================================================================
--- src/OFData.m
+++ src/OFData.m
@@ -29,10 +29,11 @@
 #endif
 #import "OFIRI.h"
 #import "OFIRIHandler.h"
 #import "OFStream.h"
 #import "OFString.h"
+#import "OFSubdata.h"
 #import "OFSystemInfo.h"
 
 #import "OFInvalidArgumentException.h"
 #import "OFInvalidFormatException.h"
 #import "OFNotImplementedException.h"
@@ -561,21 +562,22 @@
 	return hash;
 }
 
 - (OFData *)subdataWithRange: (OFRange)range
 {
-	size_t itemSize;
-
 	if (range.length > SIZE_MAX - range.location ||
 	    range.location + range.length > self.count)
 		@throw [OFOutOfRangeException exception];
 
-	itemSize = self.itemSize;
+	if (![self isKindOfClass: [OFMutableData class]])
+		return [[[OFSubdata alloc] initWithData: self
+						  range: range] autorelease];
+
 	return [OFData dataWithItems: (const unsigned char *)self.items +
-				      (range.location * itemSize)
-			       count: range.length
-			    itemSize: itemSize];
+				      (range.location * self.itemSize)
+			       count: self.count
+			    itemSize: self.itemSize];
 }
 
 - (OFString *)description
 {
 	OFMutableString *ret = [OFMutableString stringWithString: @"<"];

Index: src/OFMutableAdjacentData.h
==================================================================
--- src/OFMutableAdjacentData.h
+++ src/OFMutableAdjacentData.h
@@ -20,10 +20,9 @@
 @interface OFMutableAdjacentData: OFMutableData
 {
 	unsigned char *_Nullable _items;
 	size_t _capacity, _count, _itemSize;
 	bool _freeWhenDone;
-	OFData *_Nullable _parentData;
 }
 @end
 
 OF_ASSUME_NONNULL_END

Index: src/OFSubarray.h
==================================================================
--- src/OFSubarray.h
+++ src/OFSubarray.h
@@ -21,10 +21,9 @@
 {
 	OFArray *_array;
 	OFRange _range;
 }
 
-+ (instancetype)arrayWithArray: (OFArray *)array range: (OFRange)range;
 - (instancetype)initWithArray: (OFArray *)array range: (OFRange)range;
 @end
 
 OF_ASSUME_NONNULL_END

ADDED   src/OFSubdata.h
Index: src/OFSubdata.h
==================================================================
--- src/OFSubdata.h
+++ src/OFSubdata.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2008-2023 Jonathan Schleifer <js@nil.im>
+ *
+ * All rights reserved.
+ *
+ * This file is part of ObjFW. It may be distributed under the terms of the
+ * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
+ * the packaging of this file.
+ *
+ * Alternatively, it may be distributed under the terms of the GNU General
+ * Public License, either version 2 or 3, which can be found in the file
+ * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
+ * file.
+ */
+
+#import "OFData.h"
+
+OF_ASSUME_NONNULL_BEGIN
+
+@interface OFSubdata: OFData
+{
+	OFData *_data;
+	OFRange _range;
+}
+
+- (instancetype)initWithData: (OFData *)data range: (OFRange)range;
+@end
+
+OF_ASSUME_NONNULL_END

ADDED   src/OFSubdata.m
Index: src/OFSubdata.m
==================================================================
--- src/OFSubdata.m
+++ src/OFSubdata.m
@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2008-2023 Jonathan Schleifer <js@nil.im>
+ *
+ * All rights reserved.
+ *
+ * This file is part of ObjFW. It may be distributed under the terms of the
+ * Q Public License 1.0, which can be found in the file LICENSE.QPL included in
+ * the packaging of this file.
+ *
+ * Alternatively, it may be distributed under the terms of the GNU General
+ * Public License, either version 2 or 3, which can be found in the file
+ * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
+ * file.
+ */
+
+#include "config.h"
+
+#import "OFSubdata.h"
+
+@implementation OFSubdata
+- (instancetype)initWithData: (OFData *)data range: (OFRange)range
+{
+	self = [super init];
+
+	@try {
+		/* Should usually be retain, as it's useless with a copy */
+		_data = [data copy];
+		_range = range;
+	} @catch (id e) {
+		[self release];
+		@throw e;
+	}
+
+	return self;
+}
+
+- (void)dealloc
+{
+	[_data release];
+
+	[super dealloc];
+}
+
+- (size_t)count
+{
+	return _range.length;
+}
+
+- (size_t)itemSize
+{
+	return _data.itemSize;
+}
+
+- (const void *)items
+{
+	return (const unsigned char *)_data.items +
+	    (_range.location * _data.itemSize);
+}
+@end