diff --git a/engine/core/ime_session.h b/engine/core/ime_session.h
index e9fb4bdf..726200ec 100644
--- a/engine/core/ime_session.h
+++ b/engine/core/ime_session.h
@@ -36,6 +36,10 @@ class ImeSession
         rescoring_context_ = std::move(context);
     }
     void set_wubi_input_options(metasequoia::WubiInputOptions options);
+    const metasequoia::WubiInputOptions &wubi_input_options() const
+    {
+        return wubi_options_;
+    }
     void replace_shuangpin_raw_input(const std::string &raw_input, const std::string &raw_input_with_cases);
     void replace_quanpin_raw_input(const std::string &raw_input, const std::string &raw_input_with_cases);
     void replace_wubi_raw_input(const std::string &raw_input, const std::string &raw_input_with_cases);
diff --git a/engine/core/input_session.cpp b/engine/core/input_session.cpp
index 38bdffd6..71d8b155 100644
--- a/engine/core/input_session.cpp
+++ b/engine/core/input_session.cpp
@@ -474,6 +474,11 @@ void InputSession::set_wubi_input_options(metasequoia::WubiInputOptions options)
     }
 }
 
+const metasequoia::WubiInputOptions &InputSession::wubi_input_options() const
+{
+    return engine_.wubi_input_options();
+}
+
 const MixedExpressiveOptions &InputSession::mixed_expressive_options() const
 {
     return mixed_expressive_options_;
diff --git a/engine/core/input_session.h b/engine/core/input_session.h
index bf028e38..aa9cfbb7 100644
--- a/engine/core/input_session.h
+++ b/engine/core/input_session.h
@@ -68,6 +68,9 @@ class InputSession
     const EnglishInputOptions &english_input_options() const;
     void set_mixed_expressive_options(MixedExpressiveOptions options);
     void set_wubi_input_options(metasequoia::WubiInputOptions options);
+    // 读回当前五笔设置：公开 Session 的运行期开关要按字段改，不能整份覆盖（否则会把另一个
+    // 独立开关复位）。
+    const metasequoia::WubiInputOptions &wubi_input_options() const;
     const MixedExpressiveOptions &mixed_expressive_options() const;
     void set_dedicated_english_mode(bool enabled);
     bool dedicated_english_mode() const;
diff --git a/engine/core/session.cpp b/engine/core/session.cpp
index 773874a4..6e43b638 100644
--- a/engine/core/session.cpp
+++ b/engine/core/session.cpp
@@ -158,7 +158,10 @@ void Session::set_dedicated_english(bool enabled)
 }
 void Session::set_wubi_mixed_pinyin(bool enabled)
 {
-    impl_->session.set_wubi_input_options(WubiInputOptions{enabled});
+    // 只改混输这一个开关：整份构造 WubiInputOptions 会把运行期已生效的 z 通配一起复位。
+    metasequoia::WubiInputOptions options = impl_->session.wubi_input_options();
+    options.mixed_pinyin = enabled;
+    impl_->session.set_wubi_input_options(options);
 }
 SessionSnapshot Session::snapshot() const
 {
diff --git a/engine/tests/src/test_wubi_mixed_input_session.cpp b/engine/tests/src/test_wubi_mixed_input_session.cpp
index ffa1ea3b..0e380d07 100644
--- a/engine/tests/src/test_wubi_mixed_input_session.cpp
+++ b/engine/tests/src/test_wubi_mixed_input_session.cpp
@@ -331,6 +331,23 @@ int main()
             require(!matched.snapshot().candidates.empty(), "The four-letter code answered with nothing.");
             require(matched.snapshot().candidates.front().scheme == SchemeType::Wubi,
                     "A code the wubi table answered was not tagged as wubi.");
+
+            // set_wubi_mixed_pinyin must leave the sibling z-wildcard setting alone: a host that
+            // enabled wildcard at construction and toggles mixed at runtime keeps wildcard working.
+            SessionOptions wildcard;
+            wildcard.paths = prepare_runtime_paths(resources, root / "user-z", root / "cache-z", "v1");
+            wildcard.scheme = SchemeType::Wubi;
+            wildcard.wubi.z_wildcard = true;
+            Session z_session(wildcard);
+            z_session.set_wubi_mixed_pinyin(true);
+            for (const char letter : std::string("wz"))
+            {
+                z_session.character(letter);
+            }
+            const auto &z_candidates = z_session.snapshot().candidates;
+            require(std::any_of(z_candidates.begin(), z_candidates.end(),
+                                [](const WordItem &item) { return item.word == "你好"; }),
+                    "Toggling mixed pinyin reset the z wildcard setting.");
         }
     }
     catch (const std::exception &error)