Index: src/runtime/autorelease.m
==================================================================
--- src/runtime/autorelease.m
+++ src/runtime/autorelease.m
@@ -33,10 +33,15 @@
 #ifndef OF_OBJFW_RUNTIME
 @interface DummyObject
 - (void)release;
 @end
 #endif
+
+#ifndef OBJC_ERROR
+/* This is also used with old Apple runtimes that lack autorelease pools. */
+# define OBJC_ERROR(...) abort()
+#endif
 
 #if defined(OF_HAVE_COMPILER_TLS)
 static thread_local id *objects = NULL;
 static thread_local uintptr_t count = 0;
 static thread_local uintptr_t size = 0;