diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/huami/miband4/MiBand4FWHelper.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/huami/miband4/MiBand4FWHelper.java
new file mode 100644
index 000000000..ed2b17821
--- /dev/null
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/huami/miband4/MiBand4FWHelper.java
@@ -0,0 +1,40 @@
+/*  Copyright (C) 2017-2019 Andreas Shimokawa, Carsten Pfeiffer
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge 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 Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.devices.huami.miband4;
+
+import android.content.Context;
+import android.net.Uri;
+
+import java.io.IOException;
+
+import nodomain.freeyourgadget.gadgetbridge.devices.huami.HuamiFWHelper;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.miband4.MiBand4FirmwareInfo;
+
+public class MiBand4FWHelper extends HuamiFWHelper {
+
+    public MiBand4FWHelper(Uri uri, Context context) throws IOException {
+        super(uri, context);
+    }
+
+    @Override
+    protected void determineFirmwareInfo(byte[] wholeFirmwareBytes) {
+        firmwareInfo = new MiBand4FirmwareInfo(wholeFirmwareBytes);
+        if (!firmwareInfo.isHeaderValid()) {
+            throw new IllegalArgumentException("Not a Mi Band 4 firmware");
+        }
+    }
+}
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/huami/miband4/MiBand4FWInstallHandler.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/huami/miband4/MiBand4FWInstallHandler.java
new file mode 100644
index 000000000..f8f09a8cc
--- /dev/null
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/huami/miband4/MiBand4FWInstallHandler.java
@@ -0,0 +1,50 @@
+/*  Copyright (C) 2015-2019 Andreas Shimokawa, Carsten Pfeiffer
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge 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 Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.devices.huami.miband4;
+
+import android.content.Context;
+import android.net.Uri;
+
+import java.io.IOException;
+
+import nodomain.freeyourgadget.gadgetbridge.R;
+import nodomain.freeyourgadget.gadgetbridge.devices.huami.miband3.MiBand3FWHelper;
+import nodomain.freeyourgadget.gadgetbridge.devices.miband.AbstractMiBandFWHelper;
+import nodomain.freeyourgadget.gadgetbridge.devices.miband.AbstractMiBandFWInstallHandler;
+import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
+import nodomain.freeyourgadget.gadgetbridge.model.DeviceType;
+
+class MiBand4FWInstallHandler extends AbstractMiBandFWInstallHandler {
+    MiBand4FWInstallHandler(Uri uri, Context context) {
+        super(uri, context);
+    }
+
+    @Override
+    protected String getFwUpgradeNotice() {
+        return mContext.getString(R.string.fw_upgrade_notice_miband4, helper.getHumanFirmwareVersion());
+    }
+
+    @Override
+    protected AbstractMiBandFWHelper createHelper(Uri uri, Context context) throws IOException {
+        return new MiBand4FWHelper(uri, context);
+    }
+
+    @Override
+    protected boolean isSupportedDeviceType(GBDevice device) {
+        return device.getType() == DeviceType.MIBAND4;
+    }
+}
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/miband4/MiBand4FirmwareInfo.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/miband4/MiBand4FirmwareInfo.java
new file mode 100644
index 000000000..5b7f3fcee
--- /dev/null
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/miband4/MiBand4FirmwareInfo.java
@@ -0,0 +1,89 @@
+/*  Copyright (C) 2017-2019 Andreas Shimokawa, Carsten Pfeiffer
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge 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 Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.huami.miband4;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import nodomain.freeyourgadget.gadgetbridge.impl.GBDevice;
+import nodomain.freeyourgadget.gadgetbridge.model.DeviceType;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.HuamiFirmwareInfo;
+import nodomain.freeyourgadget.gadgetbridge.service.devices.huami.HuamiFirmwareType;
+import nodomain.freeyourgadget.gadgetbridge.util.ArrayUtils;
+
+public class MiBand4FirmwareInfo extends HuamiFirmwareInfo {
+
+    private static final byte[] FW_HEADER = new byte[]{
+            0x31, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, (byte) 0x9c, (byte) 0xe3, 0x7d, 0x5c, 0x00, 0x04
+    };
+
+    private static final int FW_HEADER_OFFSET = 16;
+
+    private static Map<Integer, String> crcToVersion = new HashMap<>();
+
+    static {
+        // firmware
+        crcToVersion.put(8969, "1.0.5.22");
+
+        // resources
+        crcToVersion.put(27412, "1.0.5.22");
+
+        // font
+        crcToVersion.put(31978, "1");
+    }
+
+    public MiBand4FirmwareInfo(byte[] bytes) {
+        super(bytes);
+    }
+
+    @Override
+    protected HuamiFirmwareType determineFirmwareType(byte[] bytes) {
+        if (ArrayUtils.equals(bytes, RES_HEADER, COMPRESSED_RES_HEADER_OFFSET) || ArrayUtils.equals(bytes, NEWRES_HEADER, COMPRESSED_RES_HEADER_OFFSET_NEW) || ArrayUtils.equals(bytes, NEWRES_HEADER, COMPRESSED_RES_HEADER_OFFSET)) {
+            return HuamiFirmwareType.RES_COMPRESSED;
+        }
+        if (ArrayUtils.equals(bytes, FW_HEADER, FW_HEADER_OFFSET)) {
+            if (searchString32BitAligned(bytes, "Mi Smart Band 4")) {
+                return HuamiFirmwareType.FIRMWARE;
+            }
+            return HuamiFirmwareType.INVALID;
+        }
+        if (ArrayUtils.startsWith(bytes, WATCHFACE_HEADER)) {
+            return HuamiFirmwareType.WATCHFACE;
+        }
+        if (ArrayUtils.startsWith(bytes, NEWFT_HEADER)) {
+            if (bytes[10] == 0x03) {
+                return HuamiFirmwareType.FONT;
+            }
+        }
+        // somebody might have unpacked the compressed res
+        if (ArrayUtils.startsWith(bytes, RES_HEADER)) {
+            return HuamiFirmwareType.RES;
+        }
+        return HuamiFirmwareType.INVALID;
+    }
+
+
+    @Override
+    public boolean isGenerallyCompatibleWith(GBDevice device) {
+        return isHeaderValid() && device.getType() == DeviceType.MIBAND4;
+    }
+
+    @Override
+    protected Map<Integer, String> getCrcMap() {
+        return crcToVersion;
+    }
+}