diff --git a/engine/MUNGA/GAUGE.h b/engine/MUNGA/GAUGE.h
index 63d2cba..66978e1 100644
--- a/engine/MUNGA/GAUGE.h
+++ b/engine/MUNGA/GAUGE.h
@@ -203,9 +203,15 @@ template <class T> GaugeConnectionDirectOf<T>::GaugeConnectionDirectOf(
 	//
 	if (data_source == NULL)
 	{
+		// Desktop gauge modes (BT_DEV_GAUGES dev composite OR L4MFDSPLIT
+		// single-window cockpit) wake the gauge renderer off the pod, where
+		// some attribute sources bind NULL; bind a static zero so the gauge
+		// reads 0 instead of AV'ing here (and in Update()).  The pod path
+		// binds every source, so this never triggers there -- byte-unchanged.
 		static int s_devGauges = -1;
 		if (s_devGauges < 0)
-			s_devGauges = (getenv("BT_DEV_GAUGES") != NULL) ? 1 : 0;
+			s_devGauges = (getenv("BT_DEV_GAUGES") != NULL ||
+			               getenv("L4MFDSPLIT")   != NULL) ? 1 : 0;
 		if (s_devGauges)
 		{
 			static T s_gaugeNullSource = T();