Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -676,10 +676,45 @@
 			AC_SUBST(TESTS_STATIC_LIB, tests.a)
 			TESTS_LIBS="$TESTS_LIBS -framework CoreFoundation"
 		])
 		;;
 esac
+
+AC_MSG_CHECKING(whether Objective C compiler supports ARC)
+old_OBJCFLAGS="$OBJCFLAGS"
+OBJCFLAGS="$OBJCFLAGS -fobjc-arc -fobjc-arc-exceptions"
+AC_TRY_COMPILE([
+	#ifdef __has_attribute
+	# if __has_attribute(objc_root_class)
+	__attribute__((__objc_root_class__))
+	# endif
+	#endif
+	@interface Foo
+	{
+		struct objc_class *_isa;
+	}
+
+	+ (id)alloc;
+	@end
+
+	@implementation Foo
+	+ (id)alloc
+	{
+		return (id)0;
+	}
+	@end
+], [
+	__weak id foo = [Foo alloc];
+	(void)foo;
+], [
+	AC_MSG_RESULT(yes)
+	AC_DEFINE(COMPILER_SUPPORTS_ARC, 1, [Whether the compiler supports ARC])
+	AC_SUBST(RUNTIME_ARC_TESTS_M, RuntimeARCTests.m)
+], [
+	AC_MSG_RESULT(no)
+])
+OBJCFLAGS="$old_OBJCFLAGS"
 
 AC_C_BIGENDIAN([
 	AC_DEFINE(OF_BIG_ENDIAN, 1, [Whether we are big endian])
 ])
 AS_IF([test x"$ac_cv_c_bigendian" = x"universal"], [

Index: extra.mk.in
==================================================================
--- extra.mk.in
+++ extra.mk.in
@@ -64,10 +64,11 @@
 OF_SCTP_SOCKET_M = @OF_SCTP_SOCKET_M@
 OF_SELECT_KERNEL_EVENT_OBSERVER_M = @OF_SELECT_KERNEL_EVENT_OBSERVER_M@
 REEXPORT_RUNTIME = @REEXPORT_RUNTIME@
 REEXPORT_RUNTIME_FRAMEWORK = @REEXPORT_RUNTIME_FRAMEWORK@
 RUNTIME = @RUNTIME@
+RUNTIME_ARC_TESTS_M = @RUNTIME_ARC_TESTS_M@
 RUNTIME_AUTORELEASE_M = @RUNTIME_AUTORELEASE_M@
 RUNTIME_FRAMEWORK_LIBS = @RUNTIME_FRAMEWORK_LIBS@
 RUNTIME_INSTANCE_M = @RUNTIME_INSTANCE_M@
 RUNTIME_LIBS = @RUNTIME_LIBS@
 RUN_TESTS = @RUN_TESTS@

Index: tests/Makefile
==================================================================
--- tests/Makefile
+++ tests/Makefile
@@ -36,10 +36,11 @@
        OFXMLElementBuilderTests.m	\
        OFXMLNodeTests.m			\
        OFXMLParserTests.m		\
        PBKDF2Tests.m			\
        RuntimeTests.m			\
+       ${RUNTIME_ARC_TESTS_M}		\
        ScryptTests.m			\
        TestsAppDelegate.m		\
        ${USE_SRCS_FILES}		\
        ${USE_SRCS_PLUGINS}		\
        ${USE_SRCS_SOCKETS}		\
@@ -201,8 +202,9 @@
 
 ${PROG_NOINST}.3dsx: ${PROG_NOINST}
 	3dsxtool $< $@
 
 CPPFLAGS += -I../src -I../src/exceptions -I../src/runtime -I.. -DSTDOUT
+OBJCFLAGS_RuntimeARCTests.m = -fobjc-arc -fobjc-arc-exceptions
 LIBS := ${TESTS_LIBS} ${LIBS}
 LDFLAGS += ${MAP_LDFLAGS}
 LD = ${OBJC}

ADDED   tests/RuntimeARCTests.m
Index: tests/RuntimeARCTests.m
==================================================================
--- tests/RuntimeARCTests.m
+++ tests/RuntimeARCTests.m
@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017,
+ *               2018, 2019, 2020
+ *   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 "TestsAppDelegate.h"
+
+static OFString *module = @"Runtime (ARC)";
+
+@interface RuntimeARCTest: OFObject
+@end
+
+@implementation RuntimeARCTest
+- (instancetype)init
+{
+	self = [super init];
+
+	@throw [OFException exception];
+
+	return self;
+}
+@end
+
+@implementation TestsAppDelegate (RuntimeARCTests)
+- (void)runtimeARCTests
+{
+	id object;
+
+	EXPECT_EXCEPTION(@"Exceptions in init", OFException,
+	    object = [[RuntimeARCTest alloc] init])
+}
+@end

Index: tests/TestsAppDelegate.h
==================================================================
--- tests/TestsAppDelegate.h
+++ tests/TestsAppDelegate.h
@@ -175,10 +175,14 @@
 @end
 
 @interface TestsAppDelegate (RuntimeTests)
 - (void)runtimeTests;
 @end
+
+@interface TestsAppDelegate (RuntimeARCTests)
+- (void)runtimeARCTests;
+@end
 
 @interface TestsAppDelegate (OFRIPEMD160HashTests)
 - (void)RIPEMD160HashTests;
 @end
 

Index: tests/TestsAppDelegate.m
==================================================================
--- tests/TestsAppDelegate.m
+++ tests/TestsAppDelegate.m
@@ -312,10 +312,13 @@
 	[[OFFileManager defaultManager]
 	    changeCurrentDirectoryPath: @"/apps/objfw-tests"];
 #endif
 
 	[self runtimeTests];
+#ifdef COMPILER_SUPPORTS_ARC
+	[self runtimeARCTests];
+#endif
 	[self objectTests];
 	[self methodSignatureTests];
 	[self invocationTests];
 	[self forwardingTests];
 #ifdef OF_HAVE_BLOCKS