Index: src/OFObject.m
==================================================================
--- src/OFObject.m
+++ src/OFObject.m
@@ -234,13 +234,13 @@
 						       selector: _cmd];
 
 	method->method_imp = newimp;
 
 	/* Update the dtable if necessary */
-	if (sarray_get_safe(self->class_pointer->dtable,
+	if (sarray_get_safe(((Class)self->class_pointer)->dtable,
 	    (sidx)method->method_name->sel_id))
-		sarray_at_put_safe(self->class_pointer->dtable,
+		sarray_at_put_safe(((Class)self->class_pointer)->dtable,
 		    (sidx)method->method_name->sel_id, method->method_imp);
 
 	return oldimp;
 #endif
 }
@@ -287,12 +287,13 @@
 						       selector: _cmd];
 
 	method->method_imp = newimp;
 
 	/* Update the dtable if necessary */
-	if (sarray_get_safe(self->dtable, (sidx)method->method_name->sel_id))
-		sarray_at_put_safe(self->dtable,
+	if (sarray_get_safe(((Class)self)->dtable,
+	    (sidx)method->method_name->sel_id))
+		sarray_at_put_safe(((Class)self)->dtable,
 		    (sidx)method->method_name->sel_id, method->method_imp);
 
 	return oldimp;
 #endif
 }