Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -404,10 +404,11 @@
 case "$host_os" in
 	darwin*)
 		AC_SUBST(LDFLAGS_REEXPORT, ["-Wl,-reexport-lobjfw"])
 		AS_IF([test x"$objc_runtime" = x"Apple runtime"], [
 			AC_SUBST(REEXPORT_LIBOBJC, ["-Wl,-reexport-lobjc"])
+			LDFLAGS="$LDFLAGS -Wl,-U,_CFRetain"
 		])
 
 		AS_IF([test x"$objc_runtime" = x"ObjFW runtime"], [
 			AS_IF([test x"$exception_type" = x"DWARF"], [
 				LDFLAGS="$LDFLAGS -Wl,-U,___gxx_personality_v0"

Index: src/OFObject.m
==================================================================
--- src/OFObject.m
+++ src/OFObject.m
@@ -56,10 +56,14 @@
 #if defined(OF_HAVE_ATOMIC_OPS)
 # import "atomic.h"
 #elif defined(OF_HAVE_THREADS)
 # import "threading.h"
 #endif
+
+#ifdef OF_APPLE_RUNTIME
+extern void* CFRetain(void*) __attribute__((__weak__));
+#endif
 
 #if defined(OF_HAVE_FORWARDING_TARGET_FOR_SELECTOR)
 extern id of_forward(id, SEL, ...);
 extern struct stret of_forward_stret(id, SEL, ...);
 #else
@@ -213,11 +217,21 @@
 #if !defined(OF_APPLE_RUNTIME) || defined(__OBJC2__)
 	objc_setUncaughtExceptionHandler(uncaughtExceptionHandler);
 #endif
 
 #if defined(OF_APPLE_RUNTIME)
-	objc_setForwardHandler((void*)&of_forward, (void*)&of_forward_stret);
+	/*
+	 * If the CFRetain symbol is defined, we are linked against
+	 * CoreFoundation. Since CoreFoundation sets its own forward handler
+	 * on load, we should not set ours, as this will break CoreFoundation.
+	 *
+	 * Unfortunately, there is no way to check if a forward handler has
+	 * already been set, so this is the best we can do.
+	 */
+	if (&CFRetain == NULL)
+		objc_setForwardHandler((void*)&of_forward,
+		    (void*)&of_forward_stret);
 #else
 	objc_setForwardHandler((IMP)&of_forward, (IMP)&of_forward_stret);
 #endif
 
 	objc_setEnumerationMutationHandler(enumerationMutationHandler);