diff --git a/fcitx5 b/fcitx5
index 4dd1326..1be1da1 160000
--- a/fcitx5
+++ b/fcitx5
@@ -1 +1 @@
-Subproject commit 4dd13267e928fec22b9d512a27548208bd83dbc2
+Subproject commit 1be1da12e09b1a61dba982f85703738551551c9c
diff --git a/macosfrontend/macosfrontend-public.h b/macosfrontend/macosfrontend-public.h
index c9787f2..f2f2511 100644
--- a/macosfrontend/macosfrontend-public.h
+++ b/macosfrontend/macosfrontend-public.h
@@ -18,4 +18,4 @@ uint16_t fcitx_string_to_osx_keycode(const char *) noexcept;
 ICUUID create_input_context(const char *appId, id client) noexcept;
 void destroy_input_context(ICUUID uuid) noexcept;
 void focus_in(ICUUID uuid) noexcept;
-void focus_out(ICUUID uuid) noexcept;
+std::string focus_out(ICUUID uuid) noexcept;
diff --git a/macosfrontend/macosfrontend.cpp b/macosfrontend/macosfrontend.cpp
index c156259..5ffcd95 100644
--- a/macosfrontend/macosfrontend.cpp
+++ b/macosfrontend/macosfrontend.cpp
@@ -14,6 +14,7 @@
 #include <fcitx-utils/event.h>
 #include <fcitx/addonmanager.h>
 #include <fcitx/inputcontext.h>
+#include <fcitx/inputmethodengine.h>
 #include <fcitx/inputpanel.h>
 #include <nlohmann/json.hpp>
 
@@ -174,12 +175,28 @@ void MacosFrontend::focusIn(ICUUID uuid) {
     useAppDefaultIM(program);
 }
 
-void MacosFrontend::focusOut(ICUUID uuid) {
+std::string MacosFrontend::focusOut(ICUUID uuid) {
     auto *ic = findIC(uuid);
     if (!ic)
-        return;
+        return "{}";
+
+    // Fake a switch input method event to call engine's deactivate method and
+    // maybe commit and clear preedit synchronously.
+    ic->isSyncEvent = true;
+    InputContextEvent event(ic, EventType::InputContextSwitchInputMethod);
+    auto engine = instance_->inputMethodEngine(ic);
+    auto entry = instance_->inputMethodEntry(ic);
+    engine->deactivate(*entry, event);
+    // At this stage panel is still shown. If removed, a following backspace
+    // will commit a BS character in VSCode.
+    ic->setDummyPreedit(false);
+    auto state = ic->getState(false);
+    ic->isSyncEvent = false;
+
     FCITX_INFO() << "Focus out " << ic->program();
     ic->focusOut();
+
+    return state;
 }
 
 MacosInputContext::MacosInputContext(MacosFrontend *frontend,
@@ -306,6 +323,7 @@ void focus_in(ICUUID uuid) noexcept {
     with_fcitx([=](Fcitx &fcitx) { return fcitx.frontend()->focusIn(uuid); });
 }
 
-void focus_out(ICUUID uuid) noexcept {
-    with_fcitx([=](Fcitx &fcitx) { return fcitx.frontend()->focusOut(uuid); });
+std::string focus_out(ICUUID uuid) noexcept {
+    return with_fcitx(
+        [=](Fcitx &fcitx) { return fcitx.frontend()->focusOut(uuid); });
 }
diff --git a/macosfrontend/macosfrontend.h b/macosfrontend/macosfrontend.h
index f415ec6..1e25781 100644
--- a/macosfrontend/macosfrontend.h
+++ b/macosfrontend/macosfrontend.h
@@ -75,7 +75,7 @@ class MacosFrontend : public AddonInstance {
     void destroyInputContext(ICUUID);
     std::string keyEvent(ICUUID, const Key &key, bool isRelease);
     void focusIn(ICUUID);
-    void focusOut(ICUUID);
+    std::string focusOut(ICUUID);
 
 private:
     Instance *instance_;
diff --git a/src/controller.swift b/src/controller.swift
index af9a410..11ef43c 100644
--- a/src/controller.swift
+++ b/src/controller.swift
@@ -44,11 +44,7 @@ class FcitxInputController: IMKInputController {
     uuid = create_input_context(appId, client)
   }
 
-  func processKey(_ unicode: UInt32, _ modsVal: UInt32, _ code: UInt16, _ isRelease: Bool) -> Bool {
-    guard let client = client as? IMKTextInput else {
-      return false
-    }
-    let res = String(process_key(uuid, unicode, modsVal, code, isRelease))
+  func processRes(_ client: IMKTextInput, _ res: String) -> Bool {
     do {
       if let data = res.data(using: .utf8) {
         let json = try JSON(data: data)
@@ -66,6 +62,14 @@ class FcitxInputController: IMKInputController {
     return false
   }
 
+  func processKey(_ unicode: UInt32, _ modsVal: UInt32, _ code: UInt16, _ isRelease: Bool) -> Bool {
+    guard let client = client as? IMKTextInput else {
+      return false
+    }
+    let res = String(process_key(uuid, unicode, modsVal, code, isRelease))
+    return processRes(client, res)
+  }
+
   // Default behavior is to recognize keyDown only
   override func recognizedEvents(_ sender: Any!) -> Int {
     let events: NSEvent.EventTypeMask = [.keyDown, .flagsChanged]
@@ -130,7 +134,12 @@ class FcitxInputController: IMKInputController {
   }
 
   override func deactivateServer(_ client: Any!) {
-    focus_out(uuid)
+    guard let client = client as? IMKTextInput else {
+      return
+    }
+    let res = String(focus_out(uuid))
+    // Maybe commit and clear preedit synchronously if user switches to ABC by Ctrl+Space.
+    let _ = processRes(client, res)
   }
 
   override func menu() -> NSMenu! {