diff --git a/specs/udmf_zdoom.txt b/specs/udmf_zdoom.txt
index a6d8acb5d..3241bf4c8 100644
--- a/specs/udmf_zdoom.txt
+++ b/specs/udmf_zdoom.txt
@@ -113,6 +113,7 @@ Note: All <bool> fields default to false unless mentioned otherwise.
       blockprojectiles = <bool>;// Line blocks all projectiles
       blockuse = <bool>;        // Line blocks all use actions
       blocksight = <bool>;      // Line blocks monster line of sight
+      blockhitscan = <bool>;    // Line blocks hitscan attacks
       locknumber = <int>;       // Line special is locked
       arg0str = <string>;       // Alternate string-based version of arg0
 
diff --git a/src/doomdata.h b/src/doomdata.h
index 46af9d6a4..55903170a 100644
--- a/src/doomdata.h
+++ b/src/doomdata.h
@@ -153,6 +153,7 @@ enum ELineFlags
 	ML_BLOCKPROJECTILE			= 0x01000000,
 	ML_BLOCKUSE					= 0x02000000,	// blocks all use actions through this line
 	ML_BLOCKSIGHT				= 0x04000000,	// blocks monster line of sight
+	ML_BLOCKHITSCAN				= 0x08000000,	// blocks hitscan attacks
 };
 
 
diff --git a/src/namedef.h b/src/namedef.h
index f2d601eb5..f7607400e 100644
--- a/src/namedef.h
+++ b/src/namedef.h
@@ -465,6 +465,7 @@ xx(blockprojectiles)
 xx(blockuse)
 xx(hidden)
 xx(blocksight)
+xx(blockhitscan)
 
 xx(Renderstyle)
 
diff --git a/src/p_lnspec.cpp b/src/p_lnspec.cpp
index a0164ab82..869fd5169 100644
--- a/src/p_lnspec.cpp
+++ b/src/p_lnspec.cpp
@@ -2545,6 +2545,7 @@ FUNC(LS_Line_SetBlocking)
 		ML_RAILING,
 		ML_BLOCKUSE,
 		ML_BLOCKSIGHT,
+		ML_BLOCKHITSCAN,
 		-1
 	};
 
diff --git a/src/p_map.cpp b/src/p_map.cpp
index 211e03056..da87481d0 100644
--- a/src/p_map.cpp
+++ b/src/p_map.cpp
@@ -3563,7 +3563,7 @@ AActor *P_LineAttack (AActor *t1, angle_t angle, fixed_t distance,
 	else tflags = TRACE_NoSky|TRACE_Impact;
 
 	if (!Trace (t1->x, t1->y, shootz, t1->Sector, vx, vy, vz, distance,
-		MF_SHOOTABLE, ML_BLOCKEVERYTHING, t1, trace,
+		MF_SHOOTABLE, ML_BLOCKEVERYTHING|ML_BLOCKHITSCAN, t1, trace,
 		tflags, hitGhosts ? CheckForGhost : CheckForSpectral))
 	{ // hit nothing
 		if (puffDefaults == NULL)
diff --git a/src/p_udmf.cpp b/src/p_udmf.cpp
index 6d935ba63..fc5964737 100644
--- a/src/p_udmf.cpp
+++ b/src/p_udmf.cpp
@@ -927,6 +927,10 @@ public:
 				Flag(ld->flags, ML_BLOCKSIGHT, key); 
 				continue;
 			
+			case NAME_blockhitscan:
+				Flag(ld->flags, ML_BLOCKHITSCAN, key); 
+				continue;
+			
 			// [Dusk] lock number
 			case NAME_Locknumber:
 				ld->locknumber = CheckInt(key);