diff --git a/config.default.h b/config.default.h
index 5da1aa1..40eeaab 100644
--- a/config.default.h
+++ b/config.default.h
@@ -481,6 +481,14 @@ BANG_BANG_OFF
 PWM value for 'off'
 */
 // #define	BANG_BANG_OFF	45
+/** \def PID_CONDITIONAL_INTEGRATION
+  PID_CONDITIONAL_INTEGRATION
+	Controls 'integral windup' by preventing the integral term from accumulating error if the heater output is saturated high/low by
+        the other terms in the PID calculation.  This is in addition to M133/I_LIMIT mechanism, and can help prevent overshoot in cases of
+        large setpoint changes which may overfill the integral term.
+	Costs 50 bytes.
+*/
+//#define PID_CONDITIONAL_INTEGRATION
 
 /**
 	move buffer size, in number of moves
diff --git a/heater.c b/heater.c
index 9fe1cc1..61fdd33 100644
--- a/heater.c
+++ b/heater.c
@@ -321,22 +321,26 @@ void heater_tick(heater_t h, temp_type_t type, uint16_t current_temp, uint16_t t
 
 		// combine factors
 		int32_t pid_output_intermed = ( // Units: counts
-			(
-				(((int32_t) heater_p) * heaters_pid[h].p_factor) +
-				(((int32_t) heaters_runtime[h].heater_i) * heaters_pid[h].i_factor) +
-				(((int32_t) heater_d) * heaters_pid[h].d_factor)
-			) / PID_SCALE
-		);
+									   (
+										(((int32_t) heater_p) * heaters_pid[h].p_factor) +
+										(((int32_t) heaters_runtime[h].heater_i) * heaters_pid[h].i_factor) +
+										(((int32_t) heater_d) * heaters_pid[h].d_factor)
+										) / PID_SCALE
+									   );
 
     // rebase and limit factors
     if (pid_output_intermed > 255) {
+      #ifdef PID_CONDITIONAL_INTEGRATION
       if (t_error > 0)
         heaters_runtime[h].heater_i -= t_error; // un-integrate
+      #endif
       pid_output = 255;
     }
     else if (pid_output_intermed < 0) {
+      #ifdef PID_CONDITIONAL_INTEGRATION
       if (t_error < 0)
         heaters_runtime[h].heater_i -= t_error; // un-integrate
+      #endif
       pid_output = 0;
     }
 		else