diff --git a/block/io.c b/block/io.c
index e8fb4ede4d..6c0bbdcf1e 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1918,7 +1918,18 @@ bdrv_co_do_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int64_t bytes,
             assert(!bs->supported_zero_flags);
         }
 
-        if (ret == -ENOTSUP && !(flags & BDRV_REQ_NO_FALLBACK)) {
+        /*
+         * TODO The ret == -EINVAL && num < alignment case is a workaround for
+         * when request_alignment is 1 on files with cache=writeback. The Linux
+         * ioctl(BLKZEROOUT) requires block alignment and will fail with
+         * EINVAL. The block layer should align the request to
+         * write_zeroes_alignment instead of trying the syscall, failing, and
+         * falling back to a bounce buffer. Doing that is not easy so for now
+         * we use a bounce buffer:
+         * https://lore.kernel.org/qemu-devel/20260109120837.2772961-1-f.ebner@proxmox.com/
+         */
+        if ((ret == -ENOTSUP || (ret == -EINVAL && num < alignment)) &&
+            !(flags & BDRV_REQ_NO_FALLBACK)) {
             /* Fall back to bounce buffer if write zeroes is unsupported */
             BdrvRequestFlags write_flags = flags & ~BDRV_REQ_ZERO_WRITE;