diff --git a/encoders/encoder.py b/encoders/encoder.py
index c12e211..c6e505e 100644
--- a/encoders/encoder.py
+++ b/encoders/encoder.py
@@ -14,8 +14,8 @@ class Encoder:
         self.pin_a = pin_a
         self.pin_b = pin_b
         self._pos = 0
-        self.a_interrupt = pyb.ExtInt(pin_a, pyb.ExtInt.IRQ_RISING_FALLING, pyb.Pin.PULL_NONE, self.a_callback)
-        self.b_interrupt = pyb.ExtInt(pin_b, pyb.ExtInt.IRQ_RISING_FALLING, pyb.Pin.PULL_NONE, self.b_callback)
+        pyb.ExtInt(pin_a, pyb.ExtInt.IRQ_RISING_FALLING, pyb.Pin.PULL_NONE, self.a_callback)
+        pyb.ExtInt(pin_b, pyb.ExtInt.IRQ_RISING_FALLING, pyb.Pin.PULL_NONE, self.b_callback)
 
     def a_callback(self, line):
         self.forward = self.pin_a.value() ^ self.pin_b.value() ^ self.reverse
diff --git a/encoders/encoder_portable.py b/encoders/encoder_portable.py
index b28e3e6..b5c3c2d 100644
--- a/encoders/encoder_portable.py
+++ b/encoders/encoder_portable.py
@@ -16,11 +16,11 @@ class Encoder:
         self.pin_b = pin_b
         self._pos = 0
         try:
-            self.a_interrupt = pin_a.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.a_callback, hard=True)
-            self.b_interrupt = pin_b.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.b_callback, hard=True)
+            pin_a.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.a_callback, hard=True)
+            pin_b.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.b_callback, hard=True)
         except TypeError:
-            self.a_interrupt = pin_a.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.a_callback)
-            self.b_interrupt = pin_b.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.b_callback)
+            pin_a.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.a_callback)
+            pin_b.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.b_callback)
 
     def a_callback(self, pin):
         self._pos += 1 if (pin() ^ self.pin_b()) else -1
diff --git a/encoders/encoder_timed.py b/encoders/encoder_timed.py
index 0a3d601..2f3a302 100644
--- a/encoders/encoder_timed.py
+++ b/encoders/encoder_timed.py
@@ -17,11 +17,11 @@ class EncoderTimed:
         self.pin_b = pin_b
         self._pos = 0
         try:
-            self.a_interrupt = pin_a.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.a_callback, hard=True)
-            self.b_interrupt = pin_b.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.b_callback, hard=True)
+            pin_a.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.a_callback, hard=True)
+            pin_b.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.b_callback, hard=True)
         except TypeError:
-            self.a_interrupt = pin_a.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.a_callback)
-            self.b_interrupt = pin_b.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.b_callback)
+            pin_a.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.a_callback)
+            pin_b.irq(trigger=Pin.IRQ_RISING | Pin.IRQ_FALLING, handler=self.b_callback)
 
     def a_callback(self, pin):
         self.forward = pin() ^ self.pin_b()