diff --git a/src/info.cpp b/src/info.cpp
index 580abbf1a..7cac3569d 100644
--- a/src/info.cpp
+++ b/src/info.cpp
@@ -258,6 +258,7 @@ PClassActor::PClassActor()
 	FastSpeed = -1.;
 	RDFactor = 1.;
 	SelfDamageFactor = 1.;
+	StealthAlpha = 0.;
 	CameraHeight = INT_MIN;
 
 	DropItems = NULL;
@@ -319,6 +320,7 @@ void PClassActor::DeriveData(PClass *newclass)
 	newa->FastSpeed = FastSpeed;
 	newa->RDFactor = RDFactor;
 	newa->SelfDamageFactor = SelfDamageFactor;
+	newa->StealthAlpha = StealthAlpha;
 	newa->CameraHeight = CameraHeight;
 	newa->HowlSound = HowlSound;
 	newa->BloodType = BloodType;
diff --git a/src/info.h b/src/info.h
index a9f79182f..6d6329f88 100644
--- a/src/info.h
+++ b/src/info.h
@@ -301,6 +301,7 @@ public:
 	double RDFactor;		// Radius damage factor
 	double SelfDamageFactor;
 	double CameraHeight;	// Height of camera when used as such
+	double StealthAlpha;	// Minmum alpha for MF_STEALTH.
 	FSoundID HowlSound;		// Sound being played when electrocuted or poisoned
 	FName BloodType;		// Blood replacement type
 	FName BloodType2;		// Bloopsplatter replacement type
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index f85f2c9eb..d218d24de 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -322,6 +322,7 @@ DEFINE_FIELD(PClassActor, WoundHealth)
 DEFINE_FIELD(PClassActor, FastSpeed)
 DEFINE_FIELD(PClassActor, RDFactor)
 DEFINE_FIELD(PClassActor, SelfDamageFactor)
+DEFINE_FIELD(PClassActor, StealthAlpha)
 DEFINE_FIELD(PClassActor, CameraHeight)
 DEFINE_FIELD(PClassActor, HowlSound)
 DEFINE_FIELD(PClassActor, BloodType)
@@ -4100,9 +4101,9 @@ void AActor::Tick ()
 			else if (visdir < 0)
 			{
 				Alpha -= 1.5/TICRATE;
-				if (Alpha < 0)
+				if (Alpha < GetClass()->StealthAlpha)
 				{
-					Alpha = 0;
+					Alpha = GetClass()->StealthAlpha;
 					visdir = 0;
 				}
 			}
diff --git a/src/scripting/thingdef_properties.cpp b/src/scripting/thingdef_properties.cpp
index 6537e2482..cf70b19ae 100644
--- a/src/scripting/thingdef_properties.cpp
+++ b/src/scripting/thingdef_properties.cpp
@@ -1440,6 +1440,16 @@ DEFINE_PROPERTY(selfdamagefactor, F, Actor)
 	static_cast<PClassActor *>(info)->SelfDamageFactor = i;
 }
 
+//==========================================================================
+//
+//==========================================================================
+DEFINE_PROPERTY(stealthalpha, F, Actor)
+{
+	PROP_DOUBLE_PARM(i, 0);
+	assert(info->IsKindOf(RUNTIME_CLASS(PClassActor)));
+	static_cast<PClassActor *>(info)->StealthAlpha = i;
+}
+
 //==========================================================================
 //
 //==========================================================================