diff --git a/bch_bindgen/src/libbcachefs_wrapper.h b/bch_bindgen/src/libbcachefs_wrapper.h
index bc4658fb..128592c3 100644
--- a/bch_bindgen/src/libbcachefs_wrapper.h
+++ b/bch_bindgen/src/libbcachefs_wrapper.h
@@ -33,5 +33,5 @@ MARK_FIX_753(blk_mode_t, BLK_OPEN_READ);
 MARK_FIX_753(blk_mode_t, BLK_OPEN_WRITE);
 MARK_FIX_753(blk_mode_t, BLK_OPEN_EXCL);
 
-MARK_FIX_753(__u64, BCH_IOCTL_SUBVOLUME_CREATE);
-MARK_FIX_753(__u64, BCH_IOCTL_SUBVOLUME_DESTROY);
+MARK_FIX_753(__u32, BCH_IOCTL_SUBVOLUME_CREATE);
+MARK_FIX_753(__u32, BCH_IOCTL_SUBVOLUME_DESTROY);
diff --git a/src/wrappers/handle.rs b/src/wrappers/handle.rs
index 48148a8f..60bdedb7 100644
--- a/src/wrappers/handle.rs
+++ b/src/wrappers/handle.rs
@@ -22,7 +22,7 @@ impl BcachefsHandle {
 
 /// I/O control commands that can be sent to a bcachefs filesystem
 /// Those are non-exhaustive 
-#[repr(u64)]
+#[repr(u32)]
 #[non_exhaustive]
 pub enum BcachefsIoctl {
     SubvolumeCreate = BCH_IOCTL_SUBVOLUME_CREATE,
@@ -47,7 +47,7 @@ impl BcachefsHandle {
     /// Type-safe [`libc::ioctl`] for bcachefs filesystems
     pub fn ioctl(&self, request: BcachefsIoctl, payload: &BcachefsIoctlPayload) -> Result<(), Errno> {
         let payload_ptr: *const libc::c_void = payload.into();
-        let ret = unsafe { libc::ioctl(self.inner.ioctl_fd, request as u64, payload_ptr) };
+        let ret = unsafe { libc::ioctl(self.inner.ioctl_fd, request as libc::Ioctl, payload_ptr) };
 
         if ret == -1 {
             Err(errno::errno())