Index: src/runtime/class.m
==================================================================
--- src/runtime/class.m
+++ src/runtime/class.m
@@ -433,11 +433,11 @@
 
 	objc_global_mutex_lock();
 
 	for (ml = cls->methodlist; ml != NULL; ml = ml->next) {
 		for (i = 0; i < ml->count; i++) {
-			if (ml->methods[i].sel.uid == sel->uid) {
+			if (sel_isEqual((SEL)&ml->methods[i].sel, sel)) {
 				const char *ret = ml->methods[i].sel.types;
 				objc_global_mutex_unlock();
 				return ret;
 			}
 		}
@@ -460,10 +460,13 @@
 		}
 	}
 
 	objc_global_mutex_unlock();
 
+	if (cls->superclass != NULL)
+		return objc_get_type_encoding(cls->superclass, sel);
+
 	return NULL;
 }
 
 IMP
 class_replaceMethod(Class cls, SEL sel, IMP newimp, const char *types)