Index: src/runtime/class.m
==================================================================
--- src/runtime/class.m
+++ src/runtime/class.m
@@ -114,17 +114,15 @@
 {
 	struct objc_method_list *ml;
 	struct objc_category **cats;
 	unsigned int i;
 
-	if (cls->dtable == NULL) {
-		if (cls->superclass != Nil)
-			cls->dtable =
-			    objc_sparsearray_copy(cls->superclass->dtable);
-		else
-			cls->dtable = objc_sparsearray_new();
-	}
+	if (cls->dtable == NULL)
+		cls->dtable = objc_sparsearray_new();
+
+	if (cls->superclass != Nil)
+		objc_sparsearray_copy(cls->dtable, cls->superclass->dtable);
 
 	for (ml = cls->methodlist; ml != NULL; ml = ml->next)
 		for (i = 0; i < ml->count; i++)
 			objc_sparsearray_set(cls->dtable,
 			    (uint32_t)ml->methods[i].sel.uid,

Index: src/runtime/runtime-private.h
==================================================================
--- src/runtime/runtime-private.h
+++ src/runtime/runtime-private.h
@@ -146,11 +146,12 @@
 extern BOOL objc_hashtable_warn_on_collision;
 extern void objc_register_selector(struct objc_abi_selector*);
 extern void objc_register_all_selectors(struct objc_abi_symtab*);
 extern void objc_free_all_selectors(void);
 extern struct objc_sparsearray* objc_sparsearray_new(void);
-extern struct objc_sparsearray* objc_sparsearray_copy(struct objc_sparsearray*);
+extern void objc_sparsearray_copy(struct objc_sparsearray*,
+    struct objc_sparsearray*);
 extern void objc_sparsearray_set(struct objc_sparsearray*, uint32_t,
     const void*);
 extern void objc_sparsearray_free(struct objc_sparsearray*);
 extern void objc_sparsearray_free_when_singlethreaded(struct objc_sparsearray*);
 extern void objc_sparsearray_cleanup(void);

Index: src/runtime/sparsearray.m
==================================================================
--- src/runtime/sparsearray.m
+++ src/runtime/sparsearray.m
@@ -61,19 +61,17 @@
 		s->buckets[i] = empty_level2;
 
 	return s;
 }
 
-struct objc_sparsearray*
-objc_sparsearray_copy(struct objc_sparsearray *src)
+void
+objc_sparsearray_copy(struct objc_sparsearray *dst,
+    struct objc_sparsearray *src)
 {
-	struct objc_sparsearray *dst;
 	size_t i, j, k;
 	uint32_t idx;
 
-	dst = objc_sparsearray_new();
-
 	for (i = 0; i < 256; i++) {
 		if (src->buckets[i]->empty)
 			continue;
 
 		for (j = 0; j < 256; j++) {
@@ -91,12 +89,10 @@
 				idx = (i << 16) | (j << 8) | k;
 				objc_sparsearray_set(dst, idx, obj);
 			}
 		}
 	}
-
-	return dst;
 }
 
 void
 objc_sparsearray_set(struct objc_sparsearray *s, uint32_t idx, const void *obj)
 {