diff --git a/src/rime/gear/key_binding_processor.h b/src/rime/gear/key_binding_processor.h
index 3649dd40b..1f7c64ccb 100644
--- a/src/rime/gear/key_binding_processor.h
+++ b/src/rime/gear/key_binding_processor.h
@@ -21,9 +21,10 @@ class KeyBindingProcessor {
 
   enum FallbackOptions {
     None = 0,
-    ShiftAsControl = (1 << 0),
-    IgnoreShift = (1 << 1),
-    All = ShiftAsControl | IgnoreShift,
+    AltAsControl = (1 << 0),
+    ShiftAsControl = (1 << 1),
+    IgnoreShift = (1 << 2),
+    All = AltAsControl | ShiftAsControl | IgnoreShift
   };
 
   struct ActionDef {
diff --git a/src/rime/gear/key_binding_processor_impl.h b/src/rime/gear/key_binding_processor_impl.h
index e283770b1..e7fa296d2 100644
--- a/src/rime/gear/key_binding_processor_impl.h
+++ b/src/rime/gear/key_binding_processor_impl.h
@@ -21,11 +21,18 @@ ProcessResult KeyBindingProcessor<T, N>::ProcessKeyEvent(
     return kAccepted;
   }
   // try to match the fallback options
-  if (key_event.ctrl() || key_event.alt()) {
+  if (key_event.ctrl() || key_event.super()) {
     return kNoop;
   }
+  if (key_event.alt() && (fallback_options & AltAsControl)) {
+    KeyEvent alt_as_control{key_event.keycode(),
+                            (key_event.modifier() & ~kAltMask) | kControlMask};
+    if (Accept(alt_as_control, ctx, keymap)) {
+      return kAccepted;
+    }
+  }
   if (key_event.shift()) {
-    if ((fallback_options & ShiftAsControl) != 0) {
+    if ((fallback_options & ShiftAsControl) && !key_event.alt()) {
       KeyEvent shift_as_control{
           key_event.keycode(),
           (key_event.modifier() & ~kShiftMask) | kControlMask};