diff --git a/meson.build b/meson.build
index 3fb31e2d..103f814e 100644
--- a/meson.build
+++ b/meson.build
@@ -113,6 +113,7 @@ vst3_plugin_sources = [
   'src/common/serialization/vst3/plugin/edit-controller.cpp',
   'src/common/serialization/vst3/plugin/edit-controller-2.cpp',
   'src/common/serialization/vst3/plugin/edit-controller-host-editing.cpp',
+  'src/common/serialization/vst3/plugin/keyswitch-controller.cpp',
   'src/common/serialization/vst3/plugin/midi-mapping.cpp',
   'src/common/serialization/vst3/plugin/note-expression-controller.cpp',
   'src/common/serialization/vst3/plugin/plugin-base.cpp',
@@ -184,6 +185,7 @@ if with_vst3
     'src/common/serialization/vst3/plugin/edit-controller.cpp',
     'src/common/serialization/vst3/plugin/edit-controller-2.cpp',
     'src/common/serialization/vst3/plugin/edit-controller-host-editing.cpp',
+    'src/common/serialization/vst3/plugin/keyswitch-controller.cpp',
     'src/common/serialization/vst3/plugin/midi-mapping.cpp',
     'src/common/serialization/vst3/plugin/note-expression-controller.cpp',
     'src/common/serialization/vst3/plugin/plugin-base.cpp',
diff --git a/src/common/serialization/vst3/README.md b/src/common/serialization/vst3/README.md
index 3d6c3469..6ad0cdac 100644
--- a/src/common/serialization/vst3/README.md
+++ b/src/common/serialization/vst3/README.md
@@ -28,6 +28,7 @@ VST3 plugin interfaces are implemented as follows:
 | `YaEditController`            | `Vst3PluginProxy`   | `IEditController`                                      |
 | `YaEditController2`           | `Vst3PluginProxy`   | `IEditController2`                                     |
 | `YaEditControllerHostEditing` | `Vst3PluginProxy`   | `IEditControllerHostEditing`                           |
+| `YaKeyswitchController`       | `Vst3PluginProxy`   | `IKeyswitchController`                                 |
 | `YaMidiMapping`               | `Vst3PluginProxy`   | `IMidiMapping`                                         |
 | `YaNoteExpressionController`  | `Vst3PluginProxy`   | `INoteExpressionController`                            |
 | `YaPluginBase`                | `Vst3PluginProxy`   | `IPluginBase`                                          |
diff --git a/src/common/serialization/vst3/plugin/keyswitch-controller.cpp b/src/common/serialization/vst3/plugin/keyswitch-controller.cpp
new file mode 100644
index 00000000..68cfbfd5
--- /dev/null
+++ b/src/common/serialization/vst3/plugin/keyswitch-controller.cpp
@@ -0,0 +1,27 @@
+// yabridge: a Wine VST bridge
+// Copyright (C) 2020-2021 Robbert van der Helm
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#include "keyswitch-controller.h"
+
+YaKeyswitchController::ConstructArgs::ConstructArgs() {}
+
+YaKeyswitchController::ConstructArgs::ConstructArgs(
+    Steinberg::IPtr<Steinberg::FUnknown> object)
+    : supported(Steinberg::FUnknownPtr<Steinberg::Vst::IKeyswitchController>(
+          object)) {}
+
+YaKeyswitchController::YaKeyswitchController(const ConstructArgs&& args)
+    : arguments(std::move(args)) {}
diff --git a/src/common/serialization/vst3/plugin/keyswitch-controller.h b/src/common/serialization/vst3/plugin/keyswitch-controller.h
new file mode 100644
index 00000000..eedbd0fc
--- /dev/null
+++ b/src/common/serialization/vst3/plugin/keyswitch-controller.h
@@ -0,0 +1,76 @@
+// yabridge: a Wine VST bridge
+// Copyright (C) 2020-2021 Robbert van der Helm
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#pragma once
+
+#include <pluginterfaces/vst/ivstnoteexpression.h>
+
+#include "../../common.h"
+#include "../base.h"
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+
+/**
+ * Wraps around `IKeyswitchController` for serialization purposes. This is
+ * instantiated as part of `Vst3PluginProxy`.
+ */
+class YaKeyswitchController : public Steinberg::Vst::IKeyswitchController {
+   public:
+    /**
+     * These are the arguments for creating a `YaKeyswitchController`.
+     */
+    struct ConstructArgs {
+        ConstructArgs();
+
+        /**
+         * Check whether an existing implementation implements
+         * `IKeyswitchController` and read arguments from it.
+         */
+        ConstructArgs(Steinberg::IPtr<Steinberg::FUnknown> object);
+
+        /**
+         * Whether the object supported this interface.
+         */
+        bool supported;
+
+        template <typename S>
+        void serialize(S& s) {
+            s.value1b(supported);
+        }
+    };
+
+    /**
+     * Instantiate this instance with arguments read from another interface
+     * implementation.
+     */
+    YaKeyswitchController(const ConstructArgs&& args);
+
+    inline bool supported() const { return arguments.supported; }
+
+    virtual int32 PLUGIN_API getKeyswitchCount(int32 busIndex,
+                                               int16 channel) override = 0;
+    virtual tresult PLUGIN_API
+    getKeyswitchInfo(int32 busIndex,
+                     int16 channel,
+                     int32 keySwitchIndex,
+                     Steinberg::Vst::KeyswitchInfo& info /*out*/) override = 0;
+
+   protected:
+    ConstructArgs arguments;
+};
+
+#pragma GCC diagnostic pop