Index: PLATFORMS.md
==================================================================
--- PLATFORMS.md
+++ PLATFORMS.md
@@ -87,13 +87,13 @@
 
 
 macOS
 -----
 
-  * OS Versions: 10.5, 10.7-10.14, Darling
+  * OS Versions: 10.5, 10.7-10.15, Darling
   * Architectures: PowerPC, PowerPC64, x86, x86_64
-  * Compilers: Clang 3.1-10.0, GCC 4.2.1
+  * Compilers: Clang 3.1-10.0, Apple GCC 4.0.1 & 4.2.1
   * Runtimes: Apple, ObjFW
 
 
 MorphOS
 -------

Index: src/OFHostAddressResolver.m
==================================================================
--- src/OFHostAddressResolver.m
+++ src/OFHostAddressResolver.m
@@ -207,11 +207,11 @@
 		return;
 	}
 
 	for (OF_KINDOF(OFDNSResourceRecord *) record in
 	    [response.answerRecords objectForKey: query.domainName]) {
-		const of_socket_address_t *address;
+		const of_socket_address_t *address = NULL;
 		OFDNSQuery *CNAMEQuery;
 
 		if ([record DNSClass] != OF_DNS_CLASS_IN)
 			continue;
 

Index: src/OFInflateStream.m
==================================================================
--- src/OFInflateStream.m
+++ src/OFInflateStream.m
@@ -228,11 +228,11 @@
 
 - (size_t)lowlevelReadIntoBuffer: (void *)buffer_
 			  length: (size_t)length
 {
 	unsigned char *buffer = buffer_;
-	uint16_t bits, tmp, value;
+	uint16_t bits = 0, tmp, value = 0;
 	size_t bytesWritten = 0;
 	unsigned char *slidingWindow;
 	uint16_t slidingWindowIndex;
 
 	if (_stream == nil)

Index: src/OFLHAArchive.h
==================================================================
--- src/OFLHAArchive.h
+++ src/OFLHAArchive.h
@@ -50,15 +50,14 @@
 /*!
  * @brief A stream for reading the current entry.
  *
  * @note This is only available in read mode.
  *
- * @note The returned stream only conforms to @ref OFReadyForReadingObserving if
- *	 the underlying stream does so, too.
+ * @note The returned stream conforms to @ref OFReadyForReadingObserving if the
+ *	 underlying stream does so, too.
  */
-@property (readonly, nonatomic)
-    OFStream <OFReadyForReadingObserving> *streamForReadingCurrentEntry;
+@property (readonly, nonatomic) OFStream *streamForReadingCurrentEntry;
 
 /*!
  * @brief Creates a new OFLHAArchive object with the specified stream.
  *
  * @param stream A stream from which the LHA archive will be read.
@@ -139,12 +138,12 @@
  * @note This is only available in write and append mode.
  *
  * @note The uncompressed size, compressed size and CRC16 of the specified
  *	 entry are ignored.
  *
- * @note The returned stream only conforms to @ref OFReadyForWritingObserving if
- *	 the underlying stream does so, too.
+ * @note The returned stream conforms to @ref OFReadyForWritingObserving if the
+ *	 underlying stream does so, too.
  *
  * @warning Calling @ref nextEntry will invalidate all streams returned by
  *	    @ref streamForReadingCurrentEntry or
  *	    @ref streamForWritingEntry:! Reading from or writing to an
  *	    invalidated stream will throw an @ref OFReadFailedException or
@@ -151,15 +150,14 @@
  *	    @ref OFWriteFailedException!
  *
  * @param entry The entry for which a stream for writing should be returned
  * @return A stream for writing the specified entry
  */
-- (OFStream <OFReadyForWritingObserving> *)
-    streamForWritingEntry: (OFLHAArchiveEntry *)entry;
+- (OFStream *)streamForWritingEntry: (OFLHAArchiveEntry *)entry;
 
 /*!
  * @brief Closes the OFLHAArchive.
  */
 - (void)close;
 @end
 
 OF_ASSUME_NONNULL_END

Index: src/OFLHAArchive.m
==================================================================
--- src/OFLHAArchive.m
+++ src/OFLHAArchive.m
@@ -203,11 +203,11 @@
 			entry: entry];
 
 	return entry;
 }
 
-- (OFStream <OFReadyForReadingObserving> *)streamForReadingCurrentEntry
+- (OFStream *)streamForReadingCurrentEntry
 {
 	if (_mode != OF_LHA_ARCHIVE_MODE_READ)
 		@throw [OFInvalidArgumentException exception];
 
 	if (_lastReturnedStream == nil)
@@ -215,12 +215,11 @@
 
 	return [[(OFLHAArchiveFileReadStream *)_lastReturnedStream
 	    retain] autorelease];
 }
 
-- (OFStream <OFReadyForWritingObserving> *)
-    streamForWritingEntry: (OFLHAArchiveEntry *)entry
+- (OFStream *)streamForWritingEntry: (OFLHAArchiveEntry *)entry
 {
 	OFString *compressionMethod;
 
 	if (_mode != OF_LHA_ARCHIVE_MODE_WRITE &&
 	    _mode != OF_LHA_ARCHIVE_MODE_APPEND)

Index: src/OFLHADecompressingStream.m
==================================================================
--- src/OFLHADecompressingStream.m
+++ src/OFLHADecompressingStream.m
@@ -138,11 +138,11 @@
 
 - (size_t)lowlevelReadIntoBuffer: (void *)buffer_
 			  length: (size_t)length
 {
 	unsigned char *buffer = buffer_;
-	uint16_t bits, value;
+	uint16_t bits = 0, value = 0;
 	size_t bytesWritten = 0;
 
 	if (_stream == nil)
 		@throw [OFNotOpenException exceptionWithObject: self];
 

Index: src/OFTarArchive.h
==================================================================
--- src/OFTarArchive.h
+++ src/OFTarArchive.h
@@ -50,15 +50,14 @@
 /*!
  * @brief A stream for reading the current entry.
  *
  * @note This is only available in read mode.
  *
- * @note The returned stream only conforms to @ref OFReadyForReadingObserving if
- *	 the underlying stream does so, too.
+ * @note The returned stream conforms to @ref OFReadyForReadingObserving if the
+ *	 underlying stream does so, too.
  */
-@property (readonly, nonatomic)
-    OFStream <OFReadyForReadingObserving> *streamForReadingCurrentEntry;
+@property (readonly, nonatomic) OFStream *streamForReadingCurrentEntry;
 
 /*!
  * @brief Creates a new OFTarArchive object with the specified stream.
  *
  * @param stream A stream from which the tar archive will be read.
@@ -136,12 +135,12 @@
 /*!
  * @brief Returns a stream for writing the specified entry.
  *
  * @note This is only available in write and append mode.
  *
- * @note The returned stream only conforms to @ref OFReadyForWritingObserving if
- *	 the underlying stream does so, too.
+ * @note The returned stream conforms to @ref OFReadyForWritingObserving if the
+ *	 underlying stream does so, too.
  *
  * @warning Calling @ref nextEntry will invalidate all streams returned by
  *	    @ref streamForReadingCurrentEntry or
  *	    @ref streamForWritingEntry:! Reading from or writing to an
  *	    invalidated stream will throw an @ref OFReadFailedException or
@@ -148,15 +147,14 @@
  *	    @ref OFWriteFailedException!
  *
  * @param entry The entry for which a stream for writing should be returned
  * @return A stream for writing the specified entry
  */
-- (OFStream <OFReadyForWritingObserving> *)
-    streamForWritingEntry: (OFTarArchiveEntry *)entry;
+- (OFStream *)streamForWritingEntry: (OFTarArchiveEntry *)entry;
 
 /*!
  * @brief Closes the OFTarArchive.
  */
 - (void)close;
 @end
 
 OF_ASSUME_NONNULL_END

Index: src/OFTarArchive.m
==================================================================
--- src/OFTarArchive.m
+++ src/OFTarArchive.m
@@ -212,11 +212,11 @@
 			entry: entry];
 
 	return entry;
 }
 
-- (OFStream <OFReadyForReadingObserving> *)streamForReadingCurrentEntry
+- (OFStream *)streamForReadingCurrentEntry
 {
 	if (_mode != OF_TAR_ARCHIVE_MODE_READ)
 		@throw [OFInvalidArgumentException exception];
 
 	if (_lastReturnedStream == nil)
@@ -224,12 +224,11 @@
 
 	return [[(OFTarArchiveFileReadStream *)_lastReturnedStream
 	    retain] autorelease];
 }
 
-- (OFStream <OFReadyForWritingObserving> *)
-    streamForWritingEntry: (OFTarArchiveEntry *)entry
+- (OFStream *)streamForWritingEntry: (OFTarArchiveEntry *)entry
 {
 	void *pool;
 
 	if (_mode != OF_TAR_ARCHIVE_MODE_WRITE &&
 	    _mode != OF_TAR_ARCHIVE_MODE_APPEND)

Index: src/OFThread.m
==================================================================
--- src/OFThread.m
+++ src/OFThread.m
@@ -334,11 +334,11 @@
 
 	if (name != nil)
 		of_thread_set_name(
 		    [name cStringWithEncoding: [OFLocale encoding]]);
 	else
-		of_thread_set_name(class_getName(self.class));
+		of_thread_set_name(class_getName([self class]));
 }
 
 + (OFString *)name
 {
 	return [OFThread currentThread].name;

Index: src/OFZIPArchive.h
==================================================================
--- src/OFZIPArchive.h
+++ src/OFZIPArchive.h
@@ -128,10 +128,13 @@
 
 /*!
  * @brief Returns a stream for reading the specified file from the archive.
  *
  * @note This method is only available in read mode.
+ *
+ * @note The returned stream conforms to @ref OFReadyForReadingObserving if the
+ *	 underlying stream does so, too.
  *
  * @warning Calling @ref streamForReadingFile: will invalidate all streams
  *	    previously returned by @ref streamForReadingFile: or
  *	    @ref streamForWritingEntry:! Reading from or writing to an
  *	    invalidated stream will throw an @ref OFReadFailedException or
@@ -144,10 +147,13 @@
 
 /*!
  * @brief Returns a stream for writing the specified entry to the archive.
  *
  * @note This method is only available in write and append mode.
+ *
+ * @note The returned stream conforms to @ref OFReadyForWritingObserving if the
+ *	 underlying stream does so, too.
  *
  * @warning Calling @ref streamForWritingEntry: will invalidate all streams
  *	    previously returned by @ref streamForReadingFile: or
  *	    @ref streamForWritingEntry:! Reading from or writing to an
  *	    invalidated stream will throw an @ref OFReadFailedException or

Index: src/bridge/NSArray+OFObject.m
==================================================================
--- src/bridge/NSArray+OFObject.m
+++ src/bridge/NSArray+OFObject.m
@@ -19,10 +19,10 @@
 #import "OFNSArray.h"
 
 int _NSArray_OFObject_reference;
 
 @implementation NSArray (OFObject)
-- (id)OFObject
+- (OFArray *)OFObject
 {
 	return [[[OFNSArray alloc] initWithNSArray: self] autorelease];
 }
 @end

Index: src/bridge/NSDictionary+OFObject.m
==================================================================
--- src/bridge/NSDictionary+OFObject.m
+++ src/bridge/NSDictionary+OFObject.m
@@ -19,11 +19,11 @@
 #import "OFNSDictionary.h"
 
 int _NSDictionary_OFObject_reference;
 
 @implementation NSDictionary (OFObject)
-- (id)OFObject
+- (OFDictionary *)OFObject
 {
 	return [[[OFNSDictionary alloc]
 	    initWithNSDictionary: self] autorelease];
 }
 @end

Index: src/bridge/NSEnumerator+OFObject.m
==================================================================
--- src/bridge/NSEnumerator+OFObject.m
+++ src/bridge/NSEnumerator+OFObject.m
@@ -19,11 +19,11 @@
 #import "OFNSEnumerator.h"
 
 int _NSEnumerator_OFObject_reference;
 
 @implementation NSEnumerator (OFObject)
-- (id)OFObject
+- (OFEnumerator *)OFObject
 {
 	return [[[OFNSEnumerator alloc]
 	    initWithNSEnumerator: self] autorelease];
 }
 @end

Index: src/bridge/NSNumber+OFObject.m
==================================================================
--- src/bridge/NSNumber+OFObject.m
+++ src/bridge/NSNumber+OFObject.m
@@ -21,11 +21,11 @@
 #import "OFInvalidArgumentException.h"
 
 int _NSNumber_OFObject_reference;
 
 @implementation NSNumber (OFObject)
-- (id)OFObject
+- (OFNumber *)OFObject
 {
 	const char *type = self.objCType;
 
 	if (strcmp(type, "c") == 0)
 		return [OFNumber numberWithChar: self.charValue];

Index: src/bridge/NSSet+OFObject.m
==================================================================
--- src/bridge/NSSet+OFObject.m
+++ src/bridge/NSSet+OFObject.m
@@ -19,10 +19,10 @@
 #import "OFNSSet.h"
 
 int _NSSet_OFObject_reference;
 
 @implementation NSSet (OFObject)
-- (id)OFObject
+- (OFSet *)OFObject
 {
 	return [[[OFNSSet alloc] initWithNSSet: self] autorelease];
 }
 @end

Index: src/bridge/NSString+OFObject.m
==================================================================
--- src/bridge/NSString+OFObject.m
+++ src/bridge/NSString+OFObject.m
@@ -19,10 +19,10 @@
 #import "OFString.h"
 
 int _NSString_OFObject_reference;
 
 @implementation NSString (OFObject)
-- (id)OFObject
+- (OFString *)OFObject
 {
 	return [OFString stringWithUTF8String: self.UTF8String];
 }
 @end

Index: src/bridge/OFArray+NSObject.m
==================================================================
--- src/bridge/OFArray+NSObject.m
+++ src/bridge/OFArray+NSObject.m
@@ -20,10 +20,10 @@
 #import "OFArray+NSObject.h"
 
 int _OFArray_NSObject_reference;
 
 @implementation OFArray (NSObject)
-- (id)NSObject
+- (NSArray *)NSObject
 {
 	return [[[NSOFArray alloc] initWithOFArray: self] autorelease];
 }
 @end

Index: src/bridge/OFDictionary+NSObject.m
==================================================================
--- src/bridge/OFDictionary+NSObject.m
+++ src/bridge/OFDictionary+NSObject.m
@@ -20,11 +20,11 @@
 #import "OFDictionary+NSObject.h"
 
 int _OFDictionary_NSObject_reference;
 
 @implementation OFDictionary (NSObject)
-- (id)NSObject
+- (NSDictionary *)NSObject
 {
 	return [[[NSOFDictionary alloc]
 	    initWithOFDictionary: self] autorelease];
 }
 @end

Index: src/bridge/OFEnumerator+NSObject.m
==================================================================
--- src/bridge/OFEnumerator+NSObject.m
+++ src/bridge/OFEnumerator+NSObject.m
@@ -20,11 +20,11 @@
 #import "OFEnumerator+NSObject.h"
 
 int _OFEnumerator_NSObject_reference;
 
 @implementation OFEnumerator (NSObject)
-- (id)NSObject
+- (NSEnumerator *)NSObject
 {
 	return [[[NSOFEnumerator alloc]
 	    initWithOFEnumerator: self] autorelease];
 }
 @end

Index: src/bridge/OFNumber+NSObject.m
==================================================================
--- src/bridge/OFNumber+NSObject.m
+++ src/bridge/OFNumber+NSObject.m
@@ -22,11 +22,11 @@
 #import "OFInvalidArgumentException.h"
 
 int _OFNumber_NSObject_reference;
 
 @implementation OFNumber (NSObject)
-- (id)NSObject
+- (NSNumber *)NSObject
 {
 	const char *type = self.objCType;
 
 	if (strcmp(type, "B") == 0)
 		return [NSNumber numberWithBool: self.boolValue];

Index: src/bridge/OFSet+NSObject.m
==================================================================
--- src/bridge/OFSet+NSObject.m
+++ src/bridge/OFSet+NSObject.m
@@ -20,10 +20,10 @@
 #import "OFSet+NSObject.h"
 
 int _OFSet_NSObject_reference;
 
 @implementation OFSet (NSObject)
-- (id)NSObject
+- (NSSet *)NSObject
 {
 	return [[[NSOFSet alloc] initWithOFSet: self] autorelease];
 }
 @end

Index: src/bridge/OFString+NSObject.m
==================================================================
--- src/bridge/OFString+NSObject.m
+++ src/bridge/OFString+NSObject.m
@@ -22,11 +22,11 @@
 #import "OFInitializationFailedException.h"
 
 int _OFString_NSObject_reference;
 
 @implementation OFString (NSObject)
-- (id)NSObject
+- (NSString *)NSObject
 {
 	NSString *string = [NSString stringWithUTF8String: self.UTF8String];
 
 	if (string == nil)
 		@throw [OFInitializationFailedException

Index: src/exceptions/OFLockFailedException.m
==================================================================
--- src/exceptions/OFLockFailedException.m
+++ src/exceptions/OFLockFailedException.m
@@ -57,8 +57,8 @@
 
 - (OFString *)description
 {
 	return [OFString stringWithFormat:
 	    @"A lock of type %@ could not be locked: %s",
-	    _lock.class, strerror(_errNo)];
+	    [_lock class], strerror(_errNo)];
 }
 @end

Index: src/exceptions/OFStillLockedException.m
==================================================================
--- src/exceptions/OFStillLockedException.m
+++ src/exceptions/OFStillLockedException.m
@@ -52,11 +52,11 @@
 - (OFString *)description
 {
 	if (_lock != nil)
 		return [OFString stringWithFormat:
 		    @"Deallocation of a lock of type %@ even though it was "
-		    @"still locked!", _lock.class];
+		    @"still locked!", [_lock class]];
 	else
 		return @"Deallocation of a lock even though it was still "
 		    @"locked!";
 }
 @end

Index: src/exceptions/OFUnlockFailedException.m
==================================================================
--- src/exceptions/OFUnlockFailedException.m
+++ src/exceptions/OFUnlockFailedException.m
@@ -57,8 +57,8 @@
 
 - (OFString *)description
 {
 	return [OFString stringWithFormat:
 	    @"A lock of type %@ could not be unlocked: %s",
-	    _lock.class, strerror(_errNo)];
+	    [_lock class], strerror(_errNo)];
 }
 @end