diff --git a/core/input/domkeytable.js b/core/input/domkeytable.js
index b84ad45d..1b6baa67 100644
--- a/core/input/domkeytable.js
+++ b/core/input/domkeytable.js
@@ -119,7 +119,7 @@ addStandard("WakeUp", KeyTable.XF86XK_WakeUp);
 // 2.8. IME and Composition Keys
 
 addStandard("AllCandidates", KeyTable.XK_MultipleCandidate);
-addStandard("Alphanumeric", KeyTable.XK_Eisu_Shift); // could also be _Eisu_Toggle
+addStandard("Alphanumeric", KeyTable.XK_Eisu_toggle);
 addStandard("CodeInput", KeyTable.XK_Codeinput);
 addStandard("Compose", KeyTable.XK_Multi_key);
 addStandard("Convert", KeyTable.XK_Henkan);
@@ -147,7 +147,7 @@ addStandard("KanjiMode", KeyTable.XK_Kanji);
 addStandard("Katakana", KeyTable.XK_Katakana);
 addStandard("Romaji", KeyTable.XK_Romaji);
 addStandard("Zenkaku", KeyTable.XK_Zenkaku);
-addStandard("ZenkakuHanaku", KeyTable.XK_Zenkaku_Hankaku);
+addStandard("ZenkakuHankaku", KeyTable.XK_Zenkaku_Hankaku);
 
 // 2.9. General-Purpose Function Keys
 
diff --git a/core/input/keyboard.js b/core/input/keyboard.js
index ed3b1bf1..48f65cf6 100644
--- a/core/input/keyboard.js
+++ b/core/input/keyboard.js
@@ -164,6 +164,20 @@ export default class Keyboard {
             return;
         }
 
+        // Windows doesn't send proper key releases for a bunch of
+        // Japanese IM keys so we have to fake the release right away
+        const jpBadKeys = [ KeyTable.XK_Zenkaku_Hankaku,
+                            KeyTable.XK_Eisu_toggle,
+                            KeyTable.XK_Katakana,
+                            KeyTable.XK_Hiragana,
+                            KeyTable.XK_Romaji ];
+        if (browser.isWindows() && jpBadKeys.includes(keysym)) {
+            this._sendKeyEvent(keysym, code, true);
+            this._sendKeyEvent(keysym, code, false);
+            stopEvent(e);
+            return;
+        }
+
         stopEvent(e);
 
         // Possible start of AltGr sequence? (see above)
diff --git a/core/input/util.js b/core/input/util.js
index 182be7f7..58f84e55 100644
--- a/core/input/util.js
+++ b/core/input/util.js
@@ -157,6 +157,21 @@ export function getKeysym(evt) {
             }
         }
 
+        // Windows sends alternating symbols for some keys when using a
+        // Japanese layout. We have no way of synchronising with the IM
+        // running on the remote system, so we send some combined keysym
+        // instead and hope for the best.
+        if (browser.isWindows()) {
+            switch (key) {
+                case 'Zenkaku':
+                case 'Hankaku':
+                    return KeyTable.XK_Zenkaku_Hankaku;
+                case 'Romaji':
+                case 'KanaMode':
+                    return KeyTable.XK_Romaji;
+            }
+        }
+
         return DOMKeyTable[key][location];
     }
 
diff --git a/tests/test.helper.js b/tests/test.helper.js
index 5552ec48..ed65770e 100644
--- a/tests/test.helper.js
+++ b/tests/test.helper.js
@@ -186,5 +186,38 @@ describe('Helpers', function () {
                 expect(KeyboardUtil.getKeysym({code: 'NumpadDecimal', key: ',', location: 3})).to.be.equal(0xFFAC);
             });
         });
+
+        describe('Japanese IM keys on Windows', function () {
+            let origNavigator;
+            beforeEach(function () {
+                // window.navigator is a protected read-only property in many
+                // environments, so we need to redefine it whilst running these
+                // tests.
+                origNavigator = Object.getOwnPropertyDescriptor(window, "navigator");
+
+                Object.defineProperty(window, "navigator", {value: {}});
+                if (window.navigator.platform !== undefined) {
+                    // Object.defineProperty() doesn't work properly in old
+                    // versions of Chrome
+                    this.skip();
+                }
+
+                window.navigator.platform = "Windows";
+            });
+
+            afterEach(function () {
+                if (origNavigator !== undefined) {
+                    Object.defineProperty(window, "navigator", origNavigator);
+                }
+            });
+
+            const keys = { 'Zenkaku': 0xff2a, 'Hankaku': 0xff2a,
+                           'Romaji': 0xff24, 'KanaMode': 0xff24 };
+            for (let [key, keysym] of Object.entries(keys)) {
+                it(`should fake combined key for ${key} on Windows`, function () {
+                    expect(KeyboardUtil.getKeysym({code: 'FakeIM', key: key})).to.be.equal(keysym);
+                });
+            }
+        });
     });
 });
diff --git a/tests/test.keyboard.js b/tests/test.keyboard.js
index 940769e6..381cd308 100644
--- a/tests/test.keyboard.js
+++ b/tests/test.keyboard.js
@@ -219,7 +219,7 @@ describe('Key Event Handling', function () {
             }
         });
 
-        it('should toggle caps lock on key press on iOS', function (done) {
+        it('should toggle caps lock on key press on iOS', function () {
             window.navigator.platform = "iPad";
             const kbd = new Keyboard(document);
             kbd.onkeyevent = sinon.spy();
@@ -228,10 +228,9 @@ describe('Key Event Handling', function () {
             expect(kbd.onkeyevent).to.have.been.calledTwice;
             expect(kbd.onkeyevent.firstCall).to.have.been.calledWith(0xFFE5, "CapsLock", true);
             expect(kbd.onkeyevent.secondCall).to.have.been.calledWith(0xFFE5, "CapsLock", false);
-            done();
         });
 
-        it('should toggle caps lock on key press on mac', function (done) {
+        it('should toggle caps lock on key press on mac', function () {
             window.navigator.platform = "Mac";
             const kbd = new Keyboard(document);
             kbd.onkeyevent = sinon.spy();
@@ -240,10 +239,9 @@ describe('Key Event Handling', function () {
             expect(kbd.onkeyevent).to.have.been.calledTwice;
             expect(kbd.onkeyevent.firstCall).to.have.been.calledWith(0xFFE5, "CapsLock", true);
             expect(kbd.onkeyevent.secondCall).to.have.been.calledWith(0xFFE5, "CapsLock", false);
-            done();
         });
 
-        it('should toggle caps lock on key release on iOS', function (done) {
+        it('should toggle caps lock on key release on iOS', function () {
             window.navigator.platform = "iPad";
             const kbd = new Keyboard(document);
             kbd.onkeyevent = sinon.spy();
@@ -252,10 +250,9 @@ describe('Key Event Handling', function () {
             expect(kbd.onkeyevent).to.have.been.calledTwice;
             expect(kbd.onkeyevent.firstCall).to.have.been.calledWith(0xFFE5, "CapsLock", true);
             expect(kbd.onkeyevent.secondCall).to.have.been.calledWith(0xFFE5, "CapsLock", false);
-            done();
         });
 
-        it('should toggle caps lock on key release on mac', function (done) {
+        it('should toggle caps lock on key release on mac', function () {
             window.navigator.platform = "Mac";
             const kbd = new Keyboard(document);
             kbd.onkeyevent = sinon.spy();
@@ -264,10 +261,50 @@ describe('Key Event Handling', function () {
             expect(kbd.onkeyevent).to.have.been.calledTwice;
             expect(kbd.onkeyevent.firstCall).to.have.been.calledWith(0xFFE5, "CapsLock", true);
             expect(kbd.onkeyevent.secondCall).to.have.been.calledWith(0xFFE5, "CapsLock", false);
-            done();
         });
     });
 
+    describe('Japanese IM keys on Windows', function () {
+        let origNavigator;
+        beforeEach(function () {
+            // window.navigator is a protected read-only property in many
+            // environments, so we need to redefine it whilst running these
+            // tests.
+            origNavigator = Object.getOwnPropertyDescriptor(window, "navigator");
+
+            Object.defineProperty(window, "navigator", {value: {}});
+            if (window.navigator.platform !== undefined) {
+                // Object.defineProperty() doesn't work properly in old
+                // versions of Chrome
+                this.skip();
+            }
+
+            window.navigator.platform = "Windows";
+        });
+
+        afterEach(function () {
+            if (origNavigator !== undefined) {
+                Object.defineProperty(window, "navigator", origNavigator);
+            }
+        });
+
+        const keys = { 'Zenkaku': 0xff2a, 'Hankaku': 0xff2a,
+                       'Alphanumeric': 0xff30, 'Katakana': 0xff26,
+                       'Hiragana': 0xff25, 'Romaji': 0xff24,
+                       'KanaMode': 0xff24 };
+        for (let [key, keysym] of Object.entries(keys)) {
+            it(`should fake key release for ${key} on Windows`, function () {
+                let kbd = new Keyboard(document);
+                kbd.onkeyevent = sinon.spy();
+                kbd._handleKeyDown(keyevent('keydown', {code: 'FakeIM', key: key}));
+
+                expect(kbd.onkeyevent).to.have.been.calledTwice;
+                expect(kbd.onkeyevent.firstCall).to.have.been.calledWith(keysym, "FakeIM", true);
+                expect(kbd.onkeyevent.secondCall).to.have.been.calledWith(keysym, "FakeIM", false);
+            });
+        }
+    });
+
     describe('Escape AltGraph on Windows', function () {
         let origNavigator;
         beforeEach(function () {