diff --git a/SquirrelInputController.m b/SquirrelInputController.m
index 02f0ef8a4..6746a24df 100644
--- a/SquirrelInputController.m
+++ b/SquirrelInputController.m
@@ -24,7 +24,7 @@ @implementation SquirrelInputController {
   NSUInteger _caretPos;
   NSArray *_candidates;
   NSUInteger _lastModifier;
-  NSEventType _lastEventType;
+  int _lastEventCount;
   RimeSessionId _session;
   NSString *_schemaId;
   BOOL _inlinePreedit;
@@ -51,9 +51,12 @@ - (BOOL)handleEvent:(NSEvent*)event client:(id)sender
   // Returning NO means the original key down will be passed on to the client.
 
   _currentClient = sender;
-
-  NSUInteger modifiers = event.modifierFlags;
-
+  NSEventModifierFlags modifiers = event.modifierFlags & NSEventModifierFlagDeviceIndependentFlagsMask;
+  int eventCount = CGEventSourceCounterForEventType(kCGEventSourceStateCombinedSessionState, kCGEventFlagsChanged) +
+                   CGEventSourceCounterForEventType(kCGEventSourceStateCombinedSessionState, kCGEventKeyDown) +
+                   CGEventSourceCounterForEventType(kCGEventSourceStateCombinedSessionState, kCGEventLeftMouseDown) +
+                   CGEventSourceCounterForEventType(kCGEventSourceStateCombinedSessionState, kCGEventRightMouseDown) +
+                   CGEventSourceCounterForEventType(kCGEventSourceStateCombinedSessionState, kCGEventOtherMouseDown);
   BOOL handled = NO;
 
   @autoreleasepool {
@@ -78,56 +81,33 @@ - (BOOL)handleEvent:(NSEvent*)event client:(id)sender
           break;
         }
         //NSLog(@"FLAGSCHANGED client: %@, modifiers: 0x%lx", sender, modifiers);
-        int rime_modifiers = osx_modifiers_to_rime_modifiers(modifiers);
-        int rime_keycode = 0;
-        // For flags-changed event, keyCode is available since macOS 10.15 (#715)
-        Bool keyCodeAvailable = NO;
-        if (@available(macOS 10.15, *)) {
-          keyCodeAvailable = YES;
-          rime_keycode = osx_keycode_to_rime_keycode(event.keyCode, 0, 0, 0);
-          //NSLog(@"keyCode: %d", event.keyCode);
-        }
         int release_mask = 0;
         NSUInteger changes = _lastModifier ^ modifiers;
+        int rime_modifiers = osx_modifiers_to_rime_modifiers(modifiers);
+        CGKeyCode keyCode = CGEventGetIntegerValueField(event.CGEvent, kCGKeyboardEventKeycode);
+        int rime_keycode = osx_keycode_to_rime_keycode(keyCode, 0, 0, 0);
+
         if (changes & OSX_CAPITAL_MASK) {
-          if (!keyCodeAvailable) {
-            rime_keycode = XK_Caps_Lock;
-          }
-          // NOTE: rime assumes XK_Caps_Lock to be sent before modifier changes,
-          // while NSFlagsChanged event has the flag changed already.
-          // so it is necessary to revert kLockMask.
           rime_modifiers ^= kLockMask;
           [self processKey:rime_keycode modifiers:rime_modifiers];
         }
         if (changes & OSX_SHIFT_MASK) {
-          if (!keyCodeAvailable) {
-            rime_keycode = XK_Shift_L;
-          }
-          release_mask = modifiers & OSX_SHIFT_MASK ? 0 : kReleaseMask;
+          release_mask = modifiers & OSX_SHIFT_MASK ? 0 : kReleaseMask | (eventCount - _lastEventCount == 1 ? 0 : kIgnoredMask);
           [self processKey:rime_keycode modifiers:(rime_modifiers | release_mask)];
         }
         if (changes & OSX_CTRL_MASK) {
-          if (!keyCodeAvailable) {
-            rime_keycode = XK_Control_L;
-          }
-          release_mask = modifiers & OSX_CTRL_MASK ? 0 : kReleaseMask;
+          release_mask = modifiers & OSX_CTRL_MASK ? 0 : kReleaseMask | (eventCount - _lastEventCount == 1 ? 0 : kIgnoredMask);
           [self processKey:rime_keycode modifiers:(rime_modifiers | release_mask)];
         }
         if (changes & OSX_ALT_MASK) {
-          if (!keyCodeAvailable) {
-            rime_keycode = XK_Alt_L;
-          }
-          release_mask = modifiers & OSX_ALT_MASK ? 0 : kReleaseMask;
+          release_mask = modifiers & OSX_ALT_MASK ? 0 : kReleaseMask | (eventCount - _lastEventCount == 1 ? 0 : kIgnoredMask);
           [self processKey:rime_keycode modifiers:(rime_modifiers | release_mask)];
         }
         if (changes & OSX_COMMAND_MASK) {
-          if (!keyCodeAvailable) {
-            rime_keycode = XK_Super_L;
-          }
-          release_mask = modifiers & OSX_COMMAND_MASK ? 0 : kReleaseMask;
+          release_mask = modifiers & OSX_COMMAND_MASK ? 0 : kReleaseMask | (eventCount - _lastEventCount == 1 ? 0 : kIgnoredMask);
           [self processKey:rime_keycode modifiers:(rime_modifiers | release_mask)];
           // do not update UI when using Command key
-          break;
+          goto saveStatus;
         }
         [self rimeUpdate];
       } break;
@@ -158,10 +138,10 @@ - (BOOL)handleEvent:(NSEvent*)event client:(id)sender
         break;
     }
   }
-
-  _lastModifier = modifiers;
-  _lastEventType = event.type;
-
+  saveStatus: if (event.type == NSEventTypeFlagsChanged) {
+    _lastModifier = modifiers;
+    _lastEventCount = eventCount;
+  }
   return handled;
 }
 
diff --git a/librime b/librime
index 8911db66b..b87eb81ce 160000
--- a/librime
+++ b/librime
@@ -1 +1 @@
-Subproject commit 8911db66b0e5d43c2c3e47ffec06bfd10201daae
+Subproject commit b87eb81cec851094e7f16a73ca9c453f3664d6e2