diff --git a/reactos/lib/kernel32/file/iocompl.c b/reactos/lib/kernel32/file/iocompl.c
index 5913ba43271..24a2db77e17 100644
--- a/reactos/lib/kernel32/file/iocompl.c
+++ b/reactos/lib/kernel32/file/iocompl.c
@@ -187,4 +187,29 @@ CancelIo(HANDLE hFile)
   return(TRUE);
 }
 
+
+/*
+ * @unimplemented
+ */
+BOOL
+WINAPI
+CancelIoEx(IN HANDLE hFile,
+           IN LPOVERLAPPED lpOverlapped)
+{
+    UNIMPLEMENTED;
+    return FALSE;
+}
+
+
+/*
+ * @unimplemented
+ */
+BOOL
+WINAPI
+CancelSynchronousIo(IN HANDLE hThread)
+{
+    UNIMPLEMENTED;
+    return FALSE;
+}
+
 /* EOF */
diff --git a/reactos/lib/kernel32/kernel32.def b/reactos/lib/kernel32/kernel32.def
index f9a8965a9bb..28dc991eac1 100644
--- a/reactos/lib/kernel32/kernel32.def
+++ b/reactos/lib/kernel32/kernel32.def
@@ -70,6 +70,8 @@ CallNamedPipeA@28
 CallNamedPipeW@28
 CancelDeviceWakeupRequest@4
 CancelIo@4
+CancelIoEx@8
+CancelSynchronousIo@4
 CancelTimerQueueTimer@8
 CancelWaitableTimer@4
 ChangeTimerQueueTimer@16
diff --git a/reactos/w32api/include/winbase.h b/reactos/w32api/include/winbase.h
index 0f81027465c..4b5be0d3fd2 100644
--- a/reactos/w32api/include/winbase.h
+++ b/reactos/w32api/include/winbase.h
@@ -1116,6 +1116,10 @@ BOOL WINAPI CallNamedPipeA(LPCSTR,PVOID,DWORD,PVOID,DWORD,PDWORD,DWORD);
 BOOL WINAPI CallNamedPipeW(LPCWSTR,PVOID,DWORD,PVOID,DWORD,PDWORD,DWORD);
 BOOL WINAPI CancelDeviceWakeupRequest(HANDLE);
 BOOL WINAPI CancelIo(HANDLE);
+#if (_WIN32_WINNT >= 0x0600)
+BOOL WINAPI CancelIoEx(HANDLE,LPOVERLAPPED);
+BOOL WINAPI CancelSynchronousIo(HANDLE);
+#endif
 BOOL WINAPI CancelWaitableTimer(HANDLE);
 #if (_WIN32_WINNT >= 0x0501)
 BOOL WINAPI CheckNameLegalDOS8Dot3A(LPCSTR,LPSTR,DWORD,PBOOL,PBOOL);