diff --git a/src/main.c b/src/main.c
index 4686c2d..2510f37 100644
--- a/src/main.c
+++ b/src/main.c
@@ -741,8 +741,11 @@ int main(void)
 						nextState = ConvMPP;
 						mpp_state.testIdx = -1;
 
-						if(mpp_state.mppMaxPWM > CONV_PWM_MAX/10) {
+						if(mpp_state.mppMaxPWM > CONV_PWM_MAX/50) {
 							mpp_state.mppMaxPWM -= 10;
+						} else {
+							// limit has gone too low -> retry at maximum
+							mpp_state.mppMaxPWM = CONV_PWM_MAX;
 						}
 					}