diff --git a/src/doomdata.h b/src/doomdata.h
index e01bab030..f3e149591 100644
--- a/src/doomdata.h
+++ b/src/doomdata.h
@@ -371,8 +371,9 @@ struct FMapThing
 	int16_t		roll;
 	uint32_t		RenderStyle;
 	int			FloatbobPhase;
-	double SpotInnerAngle = 10;
-	double SpotOuterAngle = 25;
+	double		SpotInnerAngle = 10;
+	double		SpotOuterAngle = 25;
+	int			friendlyseeblocks;
 };
 
 
diff --git a/src/namedef.h b/src/namedef.h
index f94d00858..ab4080489 100644
--- a/src/namedef.h
+++ b/src/namedef.h
@@ -504,6 +504,7 @@ xx(ScaleX)
 xx(ScaleY)
 xx(SpotInnerAngle)
 xx(SpotOuterAngle)
+xx(FriendlySeeBlocks)
 xx(Floatbobphase)
 xx(Floatbobstrength)
 xx(Target)
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 30be37f82..09fdc3eac 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -6032,6 +6032,8 @@ AActor *P_SpawnMapThing (FMapThing *mthing, int position)
 	mobj->SpawnPoint = mthing->pos;
 	mobj->SpawnAngle = mthing->angle;
 	mobj->SpawnFlags = mthing->flags;
+	if (mthing->friendlyseeblocks > 0)
+		mobj->friendlyseeblocks = mthing->friendlyseeblocks;
 	if (mthing->FloatbobPhase >= 0 && mthing->FloatbobPhase < 64) mobj->FloatBobPhase = mthing->FloatbobPhase;
 	if (mthing->Gravity < 0) mobj->Gravity = -mthing->Gravity;
 	else if (mthing->Gravity > 0) mobj->Gravity *= mthing->Gravity;
@@ -8474,5 +8476,6 @@ void PrintMiscActorInfo(AActor *query)
 		Printf("\nSpeed= %f, velocity= x:%f, y:%f, z:%f, combined:%f.\n",
 			query->Speed, query->Vel.X, query->Vel.Y, query->Vel.Z, query->Vel.Length());
 		Printf("Scale: x:%f, y:%f\n", query->Scale.X, query->Scale.Y);
+		Printf("FriendlySeeBlocks: %d\n", query->friendlyseeblocks);
 	}
 }
diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index a0d0f1842..937f77fa8 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -1831,6 +1831,7 @@ void P_LoadThings2 (MapData * map)
 		mti[i].Alpha = -1;
 		mti[i].Health = 1;
 		mti[i].FloatbobPhase = -1;
+		mti[i].friendlyseeblocks = -1;
 	}
 	delete[] mtp;
 }
diff --git a/src/p_udmf.cpp b/src/p_udmf.cpp
index 4df2d08eb..a19a45d94 100644
--- a/src/p_udmf.cpp
+++ b/src/p_udmf.cpp
@@ -805,6 +805,10 @@ public:
 
 			case NAME_SpotOuterAngle:
 				th->SpotOuterAngle = CheckFloat(key);
+
+			case NAME_FriendlySeeBlocks:
+				CHECK_N(Zd | Zdt)
+				th->friendlyseeblocks = CheckInt(key);
 				break;
 
 			default: