diff --git a/src/opcode.rs b/src/opcode.rs
index 6e6f73f5..2df81885 100644
--- a/src/opcode.rs
+++ b/src/opcode.rs
@@ -650,21 +650,21 @@ opcode! {
 opcode! {
     /// Attempt to cancel an already issued request.
     pub struct AsyncCancel {
-        user_data: { u64 }
+        user_data: { u64 },
+        flags: { types::AsyncCancelFlags },
         ;;
-
-        // TODO flags
     }
 
     pub const CODE = sys::IORING_OP_ASYNC_CANCEL;
 
     pub fn build(self) -> Entry {
-        let AsyncCancel { user_data } = self;
+        let AsyncCancel { user_data, flags } = self;
 
         let mut sqe = sqe_zeroed();
         sqe.opcode = Self::CODE;
         sqe.fd = -1;
         sqe.__bindgen_anon_2.addr = user_data;
+        sqe.__bindgen_anon_3.cancel_flags = flags.bits();
         Entry(sqe)
     }
 }
diff --git a/src/types.rs b/src/types.rs
index db3bdcef..104c79e0 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -108,7 +108,7 @@ bitflags! {
 bitflags! {
     /// Options for [`AsyncCancel`](super::AsyncCancel) and
     /// [`Submitter::register_sync_cancel`](super::Submitter::register_sync_cancel).
-    pub(crate) struct AsyncCancelFlags: u32 {
+    pub struct AsyncCancelFlags: u32 {
         /// Cancel all requests that match the given criteria, rather
         /// than just canceling the first one found.
         ///