diff --git a/ports/atmel-samd/common-hal/pulseio/PWMOut.c b/ports/atmel-samd/common-hal/pulseio/PWMOut.c
index 1da0da8444..b627dadc54 100644
--- a/ports/atmel-samd/common-hal/pulseio/PWMOut.c
+++ b/ports/atmel-samd/common-hal/pulseio/PWMOut.c
@@ -181,7 +181,7 @@ pwmout_result_t common_hal_pulseio_pwmout_construct(pulseio_pwmout_obj_t* self,
                     mux_position = j;
                     // Claim channel.
                     tcc_channels[timer->index] |= (1 << tcc_channel(timer));
-
+                    tcc_refcount[timer->index]++;
                 }
             }
         }