diff --git a/block/block-backend.c b/block/block-backend.c
index 3199f84e96..105f0afff9 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1250,7 +1250,7 @@ int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
 
 /* To be called between exactly one pair of blk_inc/dec_in_flight() */
 static int coroutine_fn
-blk_do_pwritev_part(BlockBackend *blk, int64_t offset, unsigned int bytes,
+blk_do_pwritev_part(BlockBackend *blk, int64_t offset, int64_t bytes,
                     QEMUIOVector *qiov, size_t qiov_offset,
                     BdrvRequestFlags flags)
 {
@@ -1286,7 +1286,7 @@ blk_do_pwritev_part(BlockBackend *blk, int64_t offset, unsigned int bytes,
 }
 
 int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
-                                     unsigned int bytes,
+                                     int64_t bytes,
                                      QEMUIOVector *qiov, size_t qiov_offset,
                                      BdrvRequestFlags flags)
 {
@@ -1300,7 +1300,7 @@ int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
 }
 
 int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
-                                unsigned int bytes, QEMUIOVector *qiov,
+                                int64_t bytes, QEMUIOVector *qiov,
                                 BdrvRequestFlags flags)
 {
     return blk_co_pwritev_part(blk, offset, bytes, qiov, 0, flags);
@@ -2214,7 +2214,7 @@ void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
 }
 
 int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
-                                      int bytes, BdrvRequestFlags flags)
+                                      int64_t bytes, BdrvRequestFlags flags)
 {
     return blk_co_pwritev(blk, offset, bytes, NULL,
                           flags | BDRV_REQ_ZERO_WRITE);
diff --git a/block/trace-events b/block/trace-events
index ff397ffff4..ab56edacb4 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -6,7 +6,7 @@ bdrv_lock_medium(void *bs, bool locked) "bs %p locked %d"
 
 # block-backend.c
 blk_co_preadv(void *blk, void *bs, int64_t offset, int64_t bytes, int flags) "blk %p bs %p offset %"PRId64" bytes %" PRId64 " flags 0x%x"
-blk_co_pwritev(void *blk, void *bs, int64_t offset, unsigned int bytes, int flags) "blk %p bs %p offset %"PRId64" bytes %u flags 0x%x"
+blk_co_pwritev(void *blk, void *bs, int64_t offset, int64_t bytes, int flags) "blk %p bs %p offset %"PRId64" bytes %" PRId64 " flags 0x%x"
 blk_root_attach(void *child, void *blk, void *bs) "child %p blk %p bs %p"
 blk_root_detach(void *child, void *blk, void *bs) "child %p blk %p bs %p"
 
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index 442fd705bb..91457a081e 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -129,11 +129,11 @@ int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
                                int64_t bytes, QEMUIOVector *qiov,
                                BdrvRequestFlags flags);
 int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
-                                     unsigned int bytes,
+                                     int64_t bytes,
                                      QEMUIOVector *qiov, size_t qiov_offset,
                                      BdrvRequestFlags flags);
 int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
-                               unsigned int bytes, QEMUIOVector *qiov,
+                               int64_t bytes, QEMUIOVector *qiov,
                                BdrvRequestFlags flags);
 
 static inline int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset,
@@ -243,7 +243,7 @@ int blk_get_open_flags_from_root_state(BlockBackend *blk);
 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
                   BlockCompletionFunc *cb, void *opaque);
 int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
-                                      int bytes, BdrvRequestFlags flags);
+                                      int64_t bytes, BdrvRequestFlags flags);
 int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
                           int bytes);
 int blk_truncate(BlockBackend *blk, int64_t offset, bool exact,