diff --git a/win32ss/user/ntuser/mouse.c b/win32ss/user/ntuser/mouse.c
index df8d7a6cc70..6d410681592 100644
--- a/win32ss/user/ntuser/mouse.c
+++ b/win32ss/user/ntuser/mouse.c
@@ -227,6 +227,16 @@ UserSendMouseInput(MOUSEINPUT *pmi, BOOL bInjected)
         UserSetCursorPos(ptCursor.x, ptCursor.y, bInjected, pmi->dwExtraInfo, TRUE);
     }
 
+    if (IS_KEY_DOWN(gafAsyncKeyState, VK_SHIFT))
+        pCurInfo->ButtonsDown |= MK_SHIFT;
+    else
+        pCurInfo->ButtonsDown &= ~MK_SHIFT;
+
+    if (IS_KEY_DOWN(gafAsyncKeyState, VK_CONTROL))
+        pCurInfo->ButtonsDown |= MK_CONTROL;
+    else
+        pCurInfo->ButtonsDown &= ~MK_CONTROL;
+
     /* Left button */
     if (dwFlags & MOUSEEVENTF_LEFTDOWN)
     {