diff --git a/specs/udmf_zdoom.txt b/specs/udmf_zdoom.txt
index 797d092efa..f4af55f2df 100644
--- a/specs/udmf_zdoom.txt
+++ b/specs/udmf_zdoom.txt
@@ -197,6 +197,7 @@ Note: All <bool> fields default to false unless mentioned otherwise.
       desaturation = <float>;         // Color desaturation factor. 0 = none, 1 = full, default = 0.
       silent = <bool>;                // Actors in this sector make no sound,
       nofallingdamage = <bool>;		  // Falling damage is disabled in this sector
+	  noattack = <bool>;              // Blocks monster attacks in this sector.
       dropactors = <bool>;            // Actors drop with instantly moving floors (*)
       norespawn = <bool>;             // Players can not respawn in this sector
       soundsequence = <string>;       // The sound sequence to play when this sector moves. Placing a
diff --git a/src/namedef.h b/src/namedef.h
index 9cd0a19ecb..bb42fc76df 100644
--- a/src/namedef.h
+++ b/src/namedef.h
@@ -773,6 +773,7 @@ xx(BuiltinGetDefault)
 xx(BuiltinClassCast)
 xx(BuiltinFormat)
 xx(Damage)
+xx(Noattack)
 
 // basic type names
 xx(Default)
diff --git a/src/p_enemy.cpp b/src/p_enemy.cpp
index 2fb040a933..5841e6b994 100644
--- a/src/p_enemy.cpp
+++ b/src/p_enemy.cpp
@@ -349,7 +349,7 @@ bool AActor::CheckMeleeRange ()
 
 	double dist;
 		
-	if (!pl)
+	if (!pl || (Sector->Flags & SECF_NOATTACK))
 		return false;
 				
 	dist = Distance2D (pl);
@@ -398,7 +398,7 @@ bool P_CheckMeleeRange2 (AActor *actor)
 	double dist;
 
 
-	if (!actor->target)
+	if (!actor->target || (actor->Sector->Flags & SECF_NOATTACK))
 	{
 		return false;
 	}
@@ -445,6 +445,8 @@ bool P_CheckMissileRange (AActor *actor)
 {
 	double dist;
 		
+	if ((actor->Sector->Flags & SECF_NOATTACK)) return false;
+
 	if (!P_CheckSight (actor, actor->target, SF_SEEPASTBLOCKEVERYTHING))
 		return false;
 		
diff --git a/src/p_udmf.cpp b/src/p_udmf.cpp
index 0ba75fc4c7..27293b9188 100644
--- a/src/p_udmf.cpp
+++ b/src/p_udmf.cpp
@@ -1658,6 +1658,10 @@ public:
 					sec->planes[sector_t::ceiling].GlowHeight = (float)CheckFloat(key);
 					break;
 
+				case NAME_Noattack:
+					Flag(sec->Flags, SECF_NOATTACK, key);
+					break;
+
 				case NAME_MoreIds:
 					// delay parsing of the tag string until parsing of the sector is complete
 					// This ensures that the ID is always the first tag in the list.
diff --git a/src/r_defs.h b/src/r_defs.h
index 08c27bfd39..abf43fdf15 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -494,6 +494,7 @@ enum
 	SECF_ENDGODMODE		= 256,	// getting damaged by this sector ends god mode
 	SECF_ENDLEVEL		= 512,	// ends level when health goes below 10
 	SECF_HAZARD			= 1024,	// Change to Strife's delayed damage handling.
+	SECF_NOATTACK		= 2048,	// monsters cannot start attacks in this sector.
 
 	SECF_WASSECRET		= 1 << 30,	// a secret that was discovered
 	SECF_SECRET			= 1 << 31,	// a secret sector