diff --git a/block/qcow2-cache.c b/block/qcow2-cache.c
index 6f17a28635..03b3e03c6c 100644
--- a/block/qcow2-cache.c
+++ b/block/qcow2-cache.c
@@ -93,7 +93,7 @@ static inline bool can_clean_entry(Qcow2Cache *c, int i)
         t->lru_counter <= c->cache_clean_lru_counter;
 }
 
-void qcow2_cache_clean_unused(BlockDriverState *bs, Qcow2Cache *c)
+void qcow2_cache_clean_unused(Qcow2Cache *c)
 {
     int i = 0;
     while (i < c->size) {
diff --git a/block/qcow2.c b/block/qcow2.c
index 38e7fdc4b0..461cc7ab1c 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -706,8 +706,8 @@ static void cache_clean_timer_cb(void *opaque)
 {
     BlockDriverState *bs = opaque;
     BDRVQcow2State *s = bs->opaque;
-    qcow2_cache_clean_unused(bs, s->l2_table_cache);
-    qcow2_cache_clean_unused(bs, s->refcount_block_cache);
+    qcow2_cache_clean_unused(s->l2_table_cache);
+    qcow2_cache_clean_unused(s->refcount_block_cache);
     timer_mod(s->cache_clean_timer, qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) +
               (int64_t) s->cache_clean_interval * 1000);
 }
diff --git a/block/qcow2.h b/block/qcow2.h
index 9936cd0700..867f2e8828 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -646,7 +646,7 @@ int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
     Qcow2Cache *dependency);
 void qcow2_cache_depends_on_flush(Qcow2Cache *c);
 
-void qcow2_cache_clean_unused(BlockDriverState *bs, Qcow2Cache *c);
+void qcow2_cache_clean_unused(Qcow2Cache *c);
 int qcow2_cache_empty(BlockDriverState *bs, Qcow2Cache *c);
 
 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,