diff --git a/src/bio.c b/src/bio.c
index 69c62fc6f..cbbecb6f7 100644
--- a/src/bio.c
+++ b/src/bio.c
@@ -86,7 +86,7 @@ struct bio_job {
 void *bioProcessBackgroundJobs(void *arg);
 void lazyfreeFreeObjectFromBioThread(robj *o);
 void lazyfreeFreeDatabaseFromBioThread(dict *ht1, dict *ht2);
-void lazyfreeFreeSlotsMapFromBioThread(zskiplist *sl);
+void lazyfreeFreeSlotsMapFromBioThread(rax *rt);
 
 /* Make sure we have enough stack to perform all the things we do in the
  * main thread. */