diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/miband2/MiBand2FWHelper.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/miband2/MiBand2FWHelper.java
index a4beb56d..207aceef 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/miband2/MiBand2FWHelper.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/miband2/MiBand2FWHelper.java
@@ -56,6 +56,9 @@ public class MiBand2FWHelper extends AbstractMiBandFWHelper {
     @Override
     protected void determineFirmwareInfo(byte[] wholeFirmwareBytes) {
         firmwareInfo = new Mi2FirmwareInfo(wholeFirmwareBytes);
+        if (!firmwareInfo.isHeaderValid()) {
+            throw new IllegalArgumentException("Not a Mi Band 2 firmware");
+        }
     }
 
     @Override
diff --git a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/miband2/Mi2FirmwareInfo.java b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/miband2/Mi2FirmwareInfo.java
index c0bb6717..6e9cb0a0 100644
--- a/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/miband2/Mi2FirmwareInfo.java
+++ b/app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/miband2/Mi2FirmwareInfo.java
@@ -57,8 +57,8 @@ public class Mi2FirmwareInfo {
         return isHeaderValid() && device.getType() == DeviceType.MIBAND2;
     }
 
-    protected boolean isHeaderValid() {
-        // TODO: not sure if this is a correct check!
+    public boolean isHeaderValid() {
+        // TODO: this is certainly not a correct validation, but it works for now
         return ArrayUtils.equals(FW_HEADER, bytes, FW_HEADER_OFFSET, FW_HEADER_OFFSET + FW_HEADER.length);
     }