diff --git a/miio/airhumidifier.py b/miio/airhumidifier.py
index 8ebf08c35..2c7f7395b 100644
--- a/miio/airhumidifier.py
+++ b/miio/airhumidifier.py
@@ -136,7 +136,7 @@ def strong_mode_enabled(self) -> bool:
             if self.trans_level == 90:
                 return True
 
-        elif self.firmware_version_minor > 25:
+        elif self.firmware_version_minor > 25 or self.firmware_version_minor == 0:
             return self.mode.value == "strong"
 
         return False
@@ -148,13 +148,16 @@ def firmware_version(self) -> str:
 
     @property
     def firmware_version_major(self) -> str:
-        major, _ = self.firmware_version.rsplit('_', 1)
-        return major
+        parts = self.firmware_version.rsplit('_', 1)
+        return parts[0]
 
     @property
     def firmware_version_minor(self) -> int:
-        _, minor = self.firmware_version.rsplit('_', 1)
-        return int(minor)
+        parts = self.firmware_version.rsplit('_', 1)
+        try:
+            return int(parts[1])
+        except IndexError:
+            return 0
 
     @property
     def motor_speed(self) -> Optional[int]:
diff --git a/miio/tests/test_airhumidifier.py b/miio/tests/test_airhumidifier.py
index d9baa265d..23f2001ea 100644
--- a/miio/tests/test_airhumidifier.py
+++ b/miio/tests/test_airhumidifier.py
@@ -217,7 +217,7 @@ class DummyAirHumidifierCA1(DummyDevice, AirHumidifier):
     def __init__(self, *args, **kwargs):
         self.model = MODEL_HUMIDIFIER_CA1
         self.dummy_device_info = {
-            'fw_ver': '1.2.9_5033',
+            'fw_ver': '1.6.6',
             'token': '68ffffffffffffffffffffffffffffff',
             'otu_stat': [101, 74, 5343, 0, 5327, 407],
             'mmfree': 228248,
@@ -324,7 +324,13 @@ def test_status(self):
 
         assert self.state().firmware_version == device_info.firmware_version
         assert self.state().firmware_version_major == device_info.firmware_version.rsplit('_', 1)[0]
-        assert self.state().firmware_version_minor == int(device_info.firmware_version.rsplit('_', 1)[1])
+
+        try:
+            version_minor = int(device_info.firmware_version.rsplit('_', 1)[1])
+        except IndexError:
+            version_minor = 0
+
+        assert self.state().firmware_version_minor == version_minor
         assert self.state().strong_mode_enabled is False
 
     def test_set_mode(self):