diff --git a/gc.c b/gc.c
index 284ddaed15..11f31693c0 100644
--- a/gc.c
+++ b/gc.c
@@ -5312,17 +5312,17 @@ gc_verify_internal_consistency(VALUE dummy)
 	if (objspace_live_slots(objspace) != data.live_object_count) {
 	    fprintf(stderr, "heap_pages_final_slots: %d, objspace->profile.total_freed_objects: %d\n",
 		    (int)heap_pages_final_slots, (int)objspace->profile.total_freed_objects);
-	    rb_bug("inconsistent live slot nubmer: expect %"PRIuSIZE", but %"PRIuSIZE".", objspace_live_slots(objspace), data.live_object_count);
+	    rb_bug("inconsistent live slot number: expect %"PRIuSIZE", but %"PRIuSIZE".", objspace_live_slots(objspace), data.live_object_count);
 	}
     }
 
 #if USE_RGENGC
     if (!is_marking(objspace)) {
 	if (objspace->rgengc.old_objects != data.old_object_count) {
-	    rb_bug("inconsistent old slot nubmer: expect %"PRIuSIZE", but %"PRIuSIZE".", objspace->rgengc.old_objects, data.old_object_count);
+	    rb_bug("inconsistent old slot number: expect %"PRIuSIZE", but %"PRIuSIZE".", objspace->rgengc.old_objects, data.old_object_count);
 	}
 	if (objspace->rgengc.uncollectible_wb_unprotected_objects != data.remembered_shady_count) {
-	    rb_bug("inconsistent old slot nubmer: expect %"PRIuSIZE", but %"PRIuSIZE".", objspace->rgengc.uncollectible_wb_unprotected_objects, data.remembered_shady_count);
+	    rb_bug("inconsistent old slot number: expect %"PRIuSIZE", but %"PRIuSIZE".", objspace->rgengc.uncollectible_wb_unprotected_objects, data.remembered_shady_count);
 	}
     }
 #endif