Index: src/runtime/class.m
==================================================================
--- src/runtime/class.m
+++ src/runtime/class.m
@@ -591,22 +591,10 @@
 class_getSuperclass(Class cls)
 {
 	return cls->superclass;
 }
 
-bool
-class_isKindOfClass(Class cls1, Class cls2)
-{
-	Class iter;
-
-	for (iter = cls1; iter != Nil; iter = iter->superclass)
-		if (iter == cls2)
-			return true;
-
-	return false;
-}
-
 unsigned long
 class_getInstanceSize(Class cls)
 {
 	return cls->instance_size;
 }

Index: src/runtime/runtime.h
==================================================================
--- src/runtime/runtime.h
+++ src/runtime/runtime.h
@@ -190,11 +190,10 @@
 extern unsigned int objc_getClassList(Class*, unsigned int);
 extern Class* objc_copyClassList(unsigned int*);
 extern bool class_isMetaClass(Class);
 extern const char* class_getName(Class);
 extern Class class_getSuperclass(Class);
-extern bool class_isKindOfClass(Class, Class);
 extern unsigned long class_getInstanceSize(Class);
 extern bool class_respondsToSelector(Class, SEL);
 extern bool class_conformsToProtocol(Class, Protocol*);
 extern IMP class_getMethodImplementation(Class, SEL);
 extern IMP class_getMethodImplementation_stret(Class, SEL);