diff --git a/src/p_trace.cpp b/src/p_trace.cpp
index 16a699a38..d00a5c4cc 100644
--- a/src/p_trace.cpp
+++ b/src/p_trace.cpp
@@ -996,6 +996,9 @@ DEFINE_ACTION_FUNCTION(DTracer, Trace)
 	// say thanks to oversimplifying the user API.
 	PARAM_INT(traceFlags);
 
+	// these are internal hacks.
+	traceFlags &= ~(TRACE_PCross | TRACE_Impact);
+
 	// Trace(vector3 start, Sector sector, vector3 direction, double maxDist, ETraceFlags traceFlags)
 	bool res = Trace(DVector3(start_x, start_y, start_z), sector, DVector3(direction_x, direction_y, direction_z), maxDist,
 					 (ActorFlag)0xFFFFFFFF, 0xFFFFFFFF, nullptr, self->Results, traceFlags, &DTracer::TraceCallback, self);
diff --git a/wadsrc/static/zscript/base.txt b/wadsrc/static/zscript/base.txt
index 9db86bcda..bef1751da 100644
--- a/wadsrc/static/zscript/base.txt
+++ b/wadsrc/static/zscript/base.txt
@@ -471,8 +471,8 @@ enum ETraceStatus
 enum ETraceFlags
 {
 	TRACE_NoSky		= 1,	// Hitting the sky returns TRACE_HitNone
-	TRACE_PCross		= 2,	// Trigger SPAC_PCROSS lines
-	TRACE_Impact		= 4,	// Trigger SPAC_IMPACT lines
+	//TRACE_PCross		= 2,	// Trigger SPAC_PCROSS lines
+	//TRACE_Impact		= 4,	// Trigger SPAC_IMPACT lines
 	TRACE_PortalRestrict	= 8,	// Cannot go through portals without a static link offset.
 	TRACE_ReportPortals	= 16	// Report any portal crossing to the TraceCallback
 }