diff --git a/firmware/pump_dac.cpp b/firmware/pump_dac.cpp
index 9d6576f..4e2fa1f 100644
--- a/firmware/pump_dac.cpp
+++ b/firmware/pump_dac.cpp
@@ -30,9 +30,18 @@ static const PWMConfig pumpDacConfig = {
 
 static const uint8_t pumpDacPwmCh[] = {
     PUMP_DAC_PWM_CHANNEL_0,
-#if (AFR_CHANNELS > 1)
+
+#if (AFR_CHANNELS >= 2)
     PUMP_DAC_PWM_CHANNEL_1,
 #endif
+
+#if (AFR_CHANNELS >= 3)
+    PUMP_DAC_PWM_CHANNEL_2,
+#endif
+
+#if (AFR_CHANNELS >= 4)
+    PUMP_DAC_PWM_CHANNEL_3,
+#endif
 };
 
 static Pwm pumpDac(PUMP_DAC_PWM_DEVICE);