diff --git a/src/afd.c b/src/afd.c
index 669aba9..e03062d 100644
--- a/src/afd.c
+++ b/src/afd.c
@@ -126,64 +126,38 @@ error:
 int afd_poll(SOCKET driver_socket,
              AFD_POLL_INFO* poll_info,
              OVERLAPPED* overlapped) {
-  IO_STATUS_BLOCK iosb;
-  IO_STATUS_BLOCK* iosb_ptr;
-  HANDLE event = NULL;
+  IO_STATUS_BLOCK* iosb;
+  HANDLE event;
   void* apc_context;
   NTSTATUS status;
 
-  if (overlapped != NULL) {
-    /* Overlapped operation. */
-    iosb_ptr = (IO_STATUS_BLOCK*) &overlapped->Internal;
-    event = overlapped->hEvent;
+  /* Blocking operation is not supported. */
+  assert(overlapped != NULL);
 
-    /* Do not report iocp completion if hEvent is tagged. */
-    if ((uintptr_t) event & 1) {
-      event = (HANDLE)((uintptr_t) event & ~(uintptr_t) 1);
-      apc_context = NULL;
-    } else {
-      apc_context = overlapped;
-    }
+  iosb = (IO_STATUS_BLOCK*) &overlapped->Internal;
+  event = overlapped->hEvent;
 
-  } else {
-    /* Blocking operation. */
-    iosb_ptr = &iosb;
-    event = CreateEventW(NULL, FALSE, FALSE, NULL);
-    if (event == NULL)
-      return_map_error(-1);
+  /* Do what other windows APIs would do: if hEvent has it's lowest bit set,
+   * don't post a completion to the completion port. */
+  if ((uintptr_t) event & 1) {
+    event = (HANDLE)((uintptr_t) event & ~(uintptr_t) 1);
     apc_context = NULL;
+  } else {
+    apc_context = overlapped;
   }
 
-  iosb_ptr->Status = STATUS_PENDING;
+  iosb->Status = STATUS_PENDING;
   status = NtDeviceIoControlFile((HANDLE) driver_socket,
                                  event,
                                  NULL,
                                  apc_context,
-                                 iosb_ptr,
+                                 iosb,
                                  IOCTL_AFD_POLL,
                                  poll_info,
                                  sizeof *poll_info,
                                  poll_info,
                                  sizeof *poll_info);
 
-  if (overlapped == NULL) {
-    /* If this is a blocking operation, wait for the event to become signaled,
-     * and then grab the real status from the io status block. */
-    if (status == STATUS_PENDING) {
-      DWORD r = WaitForSingleObject(event, INFINITE);
-
-      if (r == WAIT_FAILED) {
-        DWORD error = GetLastError();
-        CloseHandle(event);
-        return_set_error(-1, error);
-      }
-
-      status = iosb_ptr->Status;
-    }
-
-    CloseHandle(event);
-  }
-
   if (status == STATUS_SUCCESS)
     return 0;
   else if (status == STATUS_PENDING)