diff --git a/pykumo/py_kumo.py b/pykumo/py_kumo.py
index 2e81e76..48fb158 100644
--- a/pykumo/py_kumo.py
+++ b/pykumo/py_kumo.py
@@ -389,7 +389,11 @@ def get_fan_speeds(self):
             )
 
         if speeds == 3:
-            valid_speeds = ["quiet", "low", "powerful"]
+            # Intentionally return all 5 speeds even though the profile reports
+            # numberOfFanSpeeds=3.  These units under-report their capability:
+            # real hardware accepts the full superQuiet..superPowerful range,
+            # as confirmed on units in the field.
+            valid_speeds = ["superQuiet", "quiet", "low", "powerful", "superPowerful"]
         elif speeds == 4:
             valid_speeds = ["quiet", "Low", "powerful", "superPowerful"]
         else:
diff --git a/tests/test_fan_speeds.py b/tests/test_fan_speeds.py
new file mode 100644
index 0000000..ca05ca5
--- /dev/null
+++ b/tests/test_fan_speeds.py
@@ -0,0 +1,85 @@
+"""Tests for get_fan_speeds() across all numberOfFanSpeeds values."""
+
+import unittest
+from unittest.mock import patch
+from pykumo.py_kumo import PyKumo
+
+
+def make_unit(num_speeds, has_auto=False):
+    """Return a minimally-mocked PyKumo with the given profile."""
+    with patch.object(PyKumo, "__init__", lambda self, *a, **kw: None):
+        unit = PyKumo.__new__(PyKumo)
+    profile = {"numberOfFanSpeeds": num_speeds}
+    if has_auto:
+        profile["hasFanSpeedAuto"] = True
+    unit._profile = profile
+    unit._status = {}
+    return unit
+
+
+class TestGetFanSpeeds(unittest.TestCase):
+    def test_3speed_full_set(self):
+        """Units reporting numberOfFanSpeeds=3 expose the full 5-speed set."""
+        unit = make_unit(3)
+        speeds = unit.get_fan_speeds()
+        self.assertEqual(
+            speeds,
+            ["superQuiet", "quiet", "low", "powerful", "superPowerful"],
+        )
+
+    def test_3speed_superquiet_is_first(self):
+        """superQuiet should be the first option for 3-speed units."""
+        unit = make_unit(3)
+        speeds = unit.get_fan_speeds()
+        self.assertEqual(speeds[0], "superQuiet")
+
+    def test_3speed_superpowerful_is_last_before_auto(self):
+        """superPowerful should be the last non-auto option for 3-speed units."""
+        unit = make_unit(3)
+        speeds = unit.get_fan_speeds()
+        self.assertEqual(speeds[-1], "superPowerful")
+
+    def test_3speed_with_auto(self):
+        """3-speed + hasFanSpeedAuto appends auto at end."""
+        unit = make_unit(3, has_auto=True)
+        speeds = unit.get_fan_speeds()
+        self.assertEqual(
+            speeds,
+            ["superQuiet", "quiet", "low", "powerful", "superPowerful", "auto"],
+        )
+
+    def test_4speed_unchanged(self):
+        """4-speed behaviour is unchanged."""
+        unit = make_unit(4)
+        speeds = unit.get_fan_speeds()
+        self.assertEqual(speeds, ["quiet", "Low", "powerful", "superPowerful"])
+
+    def test_5speed_unchanged(self):
+        """5-speed (default) behaviour is unchanged."""
+        unit = make_unit(5)
+        speeds = unit.get_fan_speeds()
+        self.assertEqual(
+            speeds, ["superQuiet", "quiet", "low", "powerful", "superPowerful"]
+        )
+
+    def test_get_fan_speeds_includes_superquiet_on_3speed(self):
+        """get_fan_speeds() must include superQuiet for 3-speed units."""
+        with patch.object(PyKumo, "__init__", lambda self, *a, **kw: None):
+            unit = PyKumo.__new__(PyKumo)
+        unit._profile = {"numberOfFanSpeeds": 3}
+        unit._status = {}
+        valid = unit.get_fan_speeds()
+        self.assertIn("superQuiet", valid)
+
+    def test_get_fan_speeds_includes_superpowerful_on_3speed(self):
+        """get_fan_speeds() must include superPowerful for 3-speed units."""
+        with patch.object(PyKumo, "__init__", lambda self, *a, **kw: None):
+            unit = PyKumo.__new__(PyKumo)
+        unit._profile = {"numberOfFanSpeeds": 3}
+        unit._status = {}
+        valid = unit.get_fan_speeds()
+        self.assertIn("superPowerful", valid)
+
+
+if __name__ == "__main__":
+    unittest.main()