diff --git a/specs/udmf_zdoom.txt b/specs/udmf_zdoom.txt
index fe64a8021..15512d9fb 100644
--- a/specs/udmf_zdoom.txt
+++ b/specs/udmf_zdoom.txt
@@ -192,6 +192,7 @@ Note: All <bool> fields default to false unless mentioned otherwise.
    208: TranslucentLine, arg0 (arg0 must be preserved)
      1: Polyobj_StartLine, arg3
      5: Polyobj_ExplicitLine, arg4
+   181: Plane_Align, arg2
    215: Teleport_Line, arg0
    222: Scroll_Texture_Model, arg0 (arg0 must be preserved)
    
diff --git a/src/actionspecials.h b/src/actionspecials.h
index e1df60c16..9ee03d477 100644
--- a/src/actionspecials.h
+++ b/src/actionspecials.h
@@ -150,7 +150,7 @@ DEFINE_SPECIAL(Thing_Hate, 177, 2, 3, 3)
 DEFINE_SPECIAL(Thing_ProjectileAimed, 178, 4, 5, 5)
 DEFINE_SPECIAL(ChangeSkill, 179, 1, 1, 1)
 DEFINE_SPECIAL(Thing_SetTranslation, 180, 2, 2, 2)
-DEFINE_SPECIAL(Plane_Align, 181, -1, -1, 2)
+DEFINE_SPECIAL(Plane_Align, 181, -1, -1, 3)
 DEFINE_SPECIAL(Line_Mirror, 182, -1, 0, 0)
 DEFINE_SPECIAL(Line_AlignCeiling, 183, 2, 2, 2)
 DEFINE_SPECIAL(Line_AlignFloor, 184, 2, 2, 2)
diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index 100f4bd10..85c958a1d 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -1702,7 +1702,11 @@ void P_SetLineID (line_t *ld)
 		case Polyobj_ExplicitLine:
 			ld->id = ld->args[4];
 			break;
-
+			
+		case Plane_Align:
+			ld->id = ld->args[2];
+			break;
+			
 		case Static_Init:
 			if (ld->args[1] == Init_SectorLink) ld->id = ld->args[0];
 			break;
diff --git a/src/p_slopes.cpp b/src/p_slopes.cpp
index 0f9098733..99dcb71b2 100644
--- a/src/p_slopes.cpp
+++ b/src/p_slopes.cpp
@@ -548,7 +548,6 @@ void P_SetSlopes ()
 		if (lines[i].special == Plane_Align)
 		{
 			lines[i].special = 0;
-			lines[i].id = lines[i].args[2];
 			if (lines[i].backsector != NULL)
 			{
 				// args[0] is for floor, args[1] is for ceiling