diff --git a/regamedll/common/const.h b/regamedll/common/const.h
index 3c9873114..d667a6b85 100644
--- a/regamedll/common/const.h
+++ b/regamedll/common/const.h
@@ -96,6 +96,11 @@
 // Goes into globalvars_t.trace_flags
 #define FTRACE_SIMPLEBOX            BIT(0)  // Traceline with a simple box
 
+// Custom flags that we can retrive in pfnShouldCollide
+// Starting from BIT(16) to reserve space for more flags for Engine
+#define FTRACE_BULLET				BIT(16)
+#define FTRACE_FLASH				BIT(17)
+
 // walkmove modes
 #define WALKMOVE_NORMAL             0 // normal walkmove
 #define WALKMOVE_WORLDONLY          1 // doesn't hit ANY entities, no matter what the solid type
diff --git a/regamedll/dlls/cbase.cpp b/regamedll/dlls/cbase.cpp
index 9bf5abef0..b1cbe149e 100644
--- a/regamedll/dlls/cbase.cpp
+++ b/regamedll/dlls/cbase.cpp
@@ -1039,6 +1039,9 @@ void CBaseEntity::__API_HOOK(FireBullets)(ULONG cShots, VectorRef vecSrc, Vector
 		vecDir = vecDirShooting + x * vecSpread.x * vecRight + y * vecSpread.y * vecUp;
 		vecEnd = vecSrc + vecDir * flDistance;
 
+#ifdef REGAMEDLL_ADD
+		gpGlobals->trace_flags = FTRACE_BULLET;
+#endif
 		UTIL_TraceLine(vecSrc, vecEnd, dont_ignore_monsters, ENT(pev), &tr);
 		tracer = 0;
 
@@ -1182,6 +1185,9 @@ void CBaseEntity::__API_HOOK(FireBuckshots)(ULONG cShots, VectorRef vecSrc, Vect
 		vecDir = vecDirShooting + x * vecSpread.x * vecRight + y * vecSpread.y * vecUp;
 		vecEnd = vecSrc + vecDir * flDistance;
 
+#ifdef REGAMEDLL_ADD
+		gpGlobals->trace_flags = FTRACE_BULLET;
+#endif
 		UTIL_TraceLine(vecSrc, vecEnd, dont_ignore_monsters, ENT(pev), &tr);
 		tracer = 0;
 
@@ -1337,6 +1343,10 @@ VectorRef CBaseEntity::__API_HOOK(FireBullets3)(VectorRef vecSrc, VectorRef vecD
 	while (iPenetration != 0)
 	{
 		ClearMultiDamage();
+
+#ifdef REGAMEDLL_ADD
+		gpGlobals->trace_flags = FTRACE_BULLET;
+#endif
 		UTIL_TraceLine(vecSrc, vecEnd, dont_ignore_monsters, ENT(pev), &tr);
 
 		if (TheBots && tr.flFraction != 1.0f)
diff --git a/regamedll/dlls/combat.cpp b/regamedll/dlls/combat.cpp
index f5ec1ce15..620c84cfd 100644
--- a/regamedll/dlls/combat.cpp
+++ b/regamedll/dlls/combat.cpp
@@ -26,6 +26,9 @@ void PlayerBlind(CBasePlayer *pPlayer, entvars_t *pevInflictor, entvars_t *pevAt
 
 void RadiusFlash_TraceLine_hook(CBasePlayer *pPlayer, entvars_t *pevInflictor, entvars_t *pevAttacker, Vector &vecSrc, Vector &vecSpot, TraceResult *tr)
 {
+#ifdef REGAMEDLL_ADD
+	gpGlobals->trace_flags = FTRACE_FLASH;
+#endif
 	UTIL_TraceLine(vecSrc, vecSpot, dont_ignore_monsters, ENT(pevInflictor), tr);
 }