diff --git a/adafruit_seesaw/attiny8x7.py b/adafruit_seesaw/attiny8x7.py
index d8e59b4..bdddf54 100644
--- a/adafruit_seesaw/attiny8x7.py
+++ b/adafruit_seesaw/attiny8x7.py
@@ -26,7 +26,8 @@ class ATtiny8x7_Pinmap:
     pwm_width = 16  # we dont actually use all 16 bits but whatever
 
     """The pins capable of PWM output"""
-    pwm_pins = (0, 1, 9, 12, 13)
+    pwm_pins = (0, 1, 9, 12, 13)  # 8 bit PWM mode
+    pwm_pins += (6, 7, 8)  # 16 bit PWM mode
 
     """No pins on this board are capable of touch input"""
     touch_pins = ()
diff --git a/adafruit_seesaw/attinyx16.py b/adafruit_seesaw/attinyx16.py
index 3ff5de3..874ccd5 100644
--- a/adafruit_seesaw/attinyx16.py
+++ b/adafruit_seesaw/attinyx16.py
@@ -25,7 +25,8 @@ class ATtinyx16_Pinmap:
     pwm_width = 16  # we dont actually use all 16 bits but whatever
 
     """The pins capable of PWM output"""
-    pwm_pins = (0, 1, 7, 11, 16)
+    pwm_pins = (0, 1, 7, 11, 16)  # 8 bit PWM mode
+    pwm_pins += (4, 5, 6)  # 16 bit PWM mode
 
     """No pins on this board are capable of touch input"""
     touch_pins = ()
diff --git a/adafruit_seesaw/seesaw.py b/adafruit_seesaw/seesaw.py
index 4857300..67e1d75 100644
--- a/adafruit_seesaw/seesaw.py
+++ b/adafruit_seesaw/seesaw.py
@@ -390,14 +390,17 @@ def get_temp(self):
 
     def set_pwm_freq(self, pin, freq):
         """Set the PWM frequency of a pin by number"""
-        if pin in self.pin_mapping.pwm_pins:
-            cmd = bytearray(
-                [self.pin_mapping.pwm_pins.index(pin), (freq >> 8), freq & 0xFF]
-            )
-            self.write(_TIMER_BASE, _TIMER_FREQ, cmd)
-        else:
+        if pin not in self.pin_mapping.pwm_pins:
             raise ValueError("Invalid PWM pin")
 
+        if self.chip_id == _SAMD09_HW_ID_CODE:
+            offset = self.pin_mapping.pwm_pins.index(pin)
+        else:
+            offset = pin
+
+        cmd = bytearray([offset, (freq >> 8), freq & 0xFF])
+        self.write(_TIMER_BASE, _TIMER_FREQ, cmd)
+
     def encoder_position(self, encoder=0):
         """The current position of the encoder"""
         buf = bytearray(4)