--- a/widget/windows/WinUtils.cpp
+++ b/widget/windows/WinUtils.cpp
@@ -935,18 +935,18 @@ WinUtils::GetMouseInputSource()
   }
   return static_cast<uint16_t>(inputSource);
 }
 
 /* static */
 bool
 WinUtils::GetIsMouseFromTouch(uint32_t aEventType)
 {
-  const int MOZ_T_I_SIGNATURE = TABLET_INK_TOUCH | TABLET_INK_SIGNATURE;
-  const int MOZ_T_I_CHECK_TCH = TABLET_INK_TOUCH | TABLET_INK_CHECK;
+  const uint32_t MOZ_T_I_SIGNATURE = TABLET_INK_TOUCH | TABLET_INK_SIGNATURE;
+  const uint32_t MOZ_T_I_CHECK_TCH = TABLET_INK_TOUCH | TABLET_INK_CHECK;
   return ((aEventType == NS_MOUSE_MOVE ||
            aEventType == NS_MOUSE_BUTTON_DOWN ||
            aEventType == NS_MOUSE_BUTTON_UP) &&
          (GetMessageExtraInfo() & MOZ_T_I_SIGNATURE) == MOZ_T_I_CHECK_TCH);
 }
 
 /* static */
 MSG