diff --git a/src/modules/systemlib/pwm_limit/pwm_limit.c b/src/modules/systemlib/pwm_limit/pwm_limit.c
index 190b315f1f..de2caf1436 100644
--- a/src/modules/systemlib/pwm_limit/pwm_limit.c
+++ b/src/modules/systemlib/pwm_limit/pwm_limit.c
@@ -142,6 +142,13 @@ void pwm_limit_calc(const bool armed, const unsigned num_channels, const uint16_
 		case PWM_LIMIT_STATE_ON:
 			for (unsigned i=0; i<num_channels; i++) {
 				effective_pwm[i] = output[i] * (max_pwm[i] - min_pwm[i])/2 + (max_pwm[i] + min_pwm[i])/2;
+
+				/* last line of defense against invalid inputs */
+				if (effective_pwm[i] < min_pwm[i]) {
+					effective_pwm[i] = min_pwm[i];
+				} else if (effective_pwm[i] > max_pwm[i]) {
+					effective_pwm[i] = max_pwm[i];
+				}
 			}
 			break;
 		default: