diff --git a/lib/ftl/ftl_core.c b/lib/ftl/ftl_core.c
index e0618b7f9..9d6bf5e60 100644
--- a/lib/ftl/ftl_core.c
+++ b/lib/ftl/ftl_core.c
@@ -136,7 +136,9 @@ ftl_io_cmpl_cb(void *arg, const struct spdk_nvme_cpl *status)
 
 	ftl_trace_completion(io->dev, io, FTL_TRACE_COMPLETION_DISK);
 
-	if (!ftl_io_dec_req(io)) {
+	ftl_io_dec_req(io);
+
+	if (ftl_io_done(io)) {
 		ftl_io_complete(io);
 	}
 }
diff --git a/lib/ftl/ftl_io.c b/lib/ftl/ftl_io.c
index 894e1ceb0..10bdf2065 100644
--- a/lib/ftl/ftl_io.c
+++ b/lib/ftl/ftl_io.c
@@ -39,7 +39,7 @@
 #include "ftl_rwb.h"
 #include "ftl_band.h"
 
-size_t
+void
 ftl_io_inc_req(struct ftl_io *io)
 {
 	struct ftl_band *band = io->band;
@@ -50,10 +50,10 @@ ftl_io_inc_req(struct ftl_io *io)
 
 	__atomic_fetch_add(&io->dev->num_inflight, 1, __ATOMIC_SEQ_CST);
 
-	return ++io->req_cnt;
+	++io->req_cnt;
 }
 
-size_t
+void
 ftl_io_dec_req(struct ftl_io *io)
 {
 	struct ftl_band *band = io->band;
@@ -68,7 +68,7 @@ ftl_io_dec_req(struct ftl_io *io)
 	assert(num_inflight > 0);
 	assert(io->req_cnt > 0);
 
-	return --io->req_cnt;
+	--io->req_cnt;
 }
 
 struct iovec *
diff --git a/lib/ftl/ftl_io.h b/lib/ftl/ftl_io.h
index f0e5565f2..b2325fb55 100644
--- a/lib/ftl/ftl_io.h
+++ b/lib/ftl/ftl_io.h
@@ -241,8 +241,8 @@ struct ftl_io *ftl_io_init_internal(const struct ftl_io_init_opts *opts);
 void ftl_io_reinit(struct ftl_io *io, spdk_ftl_fn cb,
 		   void *ctx, int flags, int type);
 void ftl_io_clear(struct ftl_io *io);
-size_t ftl_io_inc_req(struct ftl_io *io);
-size_t ftl_io_dec_req(struct ftl_io *io);
+void ftl_io_inc_req(struct ftl_io *io);
+void ftl_io_dec_req(struct ftl_io *io);
 struct iovec *ftl_io_iovec(struct ftl_io *io);
 uint64_t ftl_io_current_lba(struct ftl_io *io);
 void ftl_io_update_iovec(struct ftl_io *io, size_t lbk_cnt);
diff --git a/test/unit/lib/ftl/ftl_wptr/ftl_wptr_ut.c b/test/unit/lib/ftl/ftl_wptr/ftl_wptr_ut.c
index 778352743..b6cda88e2 100644
--- a/test/unit/lib/ftl/ftl_wptr/ftl_wptr_ut.c
+++ b/test/unit/lib/ftl/ftl_wptr/ftl_wptr_ut.c
@@ -57,8 +57,8 @@ static struct spdk_ftl_punit_range g_range = {
 #if defined(DEBUG)
 DEFINE_STUB(ftl_band_validate_md, bool, (struct ftl_band *band, const uint64_t *lba_map), true);
 #endif
-DEFINE_STUB(ftl_io_dec_req, size_t, (struct ftl_io *io), 0);
-DEFINE_STUB(ftl_io_inc_req, size_t, (struct ftl_io *io), 0);
+DEFINE_STUB_V(ftl_io_dec_req, (struct ftl_io *io));
+DEFINE_STUB_V(ftl_io_inc_req, (struct ftl_io *io));
 DEFINE_STUB_V(ftl_trace_completion, (struct spdk_ftl_dev *dev, const struct ftl_io *io,
 				     enum ftl_trace_completion completion));
 DEFINE_STUB_V(ftl_reloc_add, (struct ftl_reloc *reloc, struct ftl_band *band, size_t offset,