diff --git a/extras/conf/udb/Includes/SRB222_linedefs.cfg b/extras/conf/udb/Includes/SRB222_linedefs.cfg
index 9447a53ad..27d8454dd 100644
--- a/extras/conf/udb/Includes/SRB222_linedefs.cfg
+++ b/extras/conf/udb/Includes/SRB222_linedefs.cfg
@@ -3050,6 +3050,29 @@ udmf
 			}
 		}
 
+		439
+		{
+			title = "Change Tagged Linedef's Textures";
+			prefix = "(439)";
+			arg0
+			{
+				title = "Target linedef tag";
+				type = 15;
+			}
+			arg1
+			{
+				title = "Affected sides";
+				type = 11;
+				enum = "frontbackboth";
+			}
+			arg2
+			{
+				title = "Change unset textures?";
+				type = 11;
+				enum = "yesno";
+			}
+		}
+
 		440
 		{
 			title = "Start Metal Sonic Race";
diff --git a/src/p_setup.c b/src/p_setup.c
index 782253cbd..1476e1d43 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -3824,6 +3824,11 @@ static void P_ConvertBinaryMap(void)
 			lines[i].args[0] = sides[lines[i].sidenum[0]].textureoffset >> FRACBITS;
 			lines[i].args[1] = !!(lines[i].flags & ML_NOCLIMB);
 			break;
+		case 439: //Change tagged linedef's textures
+			lines[i].args[0] = tag;
+			lines[i].args[1] = TMSD_FRONTBACK;
+			lines[i].args[2] = !!(lines[i].flags & ML_NOCLIMB);
+			break;
 		case 441: //Condition set trigger
 			lines[i].args[0] = sides[lines[i].sidenum[0]].textureoffset >> FRACBITS;
 			break;
diff --git a/src/p_spec.c b/src/p_spec.c
index a4d358361..11a03056f 100644
--- a/src/p_spec.c
+++ b/src/p_spec.c
@@ -2776,30 +2776,33 @@ static void P_ProcessLineSpecial(line_t *line, mobj_t *mo, sector_t *callsec)
 			{
 				size_t linenum;
 				side_t *set = &sides[line->sidenum[0]], *this;
-				boolean always = !(line->flags & ML_NOCLIMB); // If noclimb: Only change mid texture if mid texture already exists on tagged lines, etc.
+				boolean always = !(line->args[2]); // If args[2] is set: Only change mid texture if mid texture already exists on tagged lines, etc.
 
 				for (linenum = 0; linenum < numlines; linenum++)
 				{
 					if (lines[linenum].special == 439)
 						continue; // Don't override other set texture lines!
 
-					if (!Tag_Find(&lines[linenum].tags, tag))
+					if (!Tag_Find(&lines[linenum].tags, line->args[0]))
 						continue; // Find tagged lines
 
 					// Front side
-					this = &sides[lines[linenum].sidenum[0]];
-					if (always || this->toptexture) this->toptexture = set->toptexture;
-					if (always || this->midtexture) this->midtexture = set->midtexture;
-					if (always || this->bottomtexture) this->bottomtexture = set->bottomtexture;
-
-					if (lines[linenum].sidenum[1] == 0xffff)
-						continue; // One-sided stops here.
+					if (line->args[1] != TMSD_BACK)
+					{
+						this = &sides[lines[linenum].sidenum[0]];
+						if (always || this->toptexture) this->toptexture = set->toptexture;
+						if (always || this->midtexture) this->midtexture = set->midtexture;
+						if (always || this->bottomtexture) this->bottomtexture = set->bottomtexture;
+					}
 
 					// Back side
-					this = &sides[lines[linenum].sidenum[1]];
-					if (always || this->toptexture) this->toptexture = set->toptexture;
-					if (always || this->midtexture) this->midtexture = set->midtexture;
-					if (always || this->bottomtexture) this->bottomtexture = set->bottomtexture;
+					if (line->args[1] != TMSD_FRONT && lines[linenum].sidenum[1] != 0xffff)
+					{
+						this = &sides[lines[linenum].sidenum[1]];
+						if (always || this->toptexture) this->toptexture = set->toptexture;
+						if (always || this->midtexture) this->midtexture = set->midtexture;
+						if (always || this->bottomtexture) this->bottomtexture = set->bottomtexture;
+					}
 				}
 			}
 			break;