diff --git a/src/maploader/udmf.cpp b/src/maploader/udmf.cpp
index c063606f2..089663398 100644
--- a/src/maploader/udmf.cpp
+++ b/src/maploader/udmf.cpp
@@ -1132,6 +1132,10 @@ public:
 			case NAME_lm_lightcolorline:
 			case NAME_lm_lightintensityline:
 			case NAME_lm_lightdistanceline:
+			case NAME_lm_sampledist_line:
+			case NAME_lm_sampledist_top:
+			case NAME_lm_sampledist_mid:
+			case NAME_lm_sampledist_bot:
 				CHECK_N(Zd | Zdt)
 				break;
 
@@ -1991,6 +1995,8 @@ public:
 				case NAME_lm_lightcolorceiling:
 				case NAME_lm_lightintensityceiling:
 				case NAME_lm_lightdistanceceiling:
+				case NAME_lm_sampledist_floor:
+				case NAME_lm_sampledist_ceiling:
 					CHECK_N(Zd | Zdt)
 					break;
 
diff --git a/src/namedef_custom.h b/src/namedef_custom.h
index 8401ec289..b24bf4a5f 100644
--- a/src/namedef_custom.h
+++ b/src/namedef_custom.h
@@ -863,6 +863,12 @@ xx(lm_lightdistancefloor)
 xx(lm_lightcolorceiling)
 xx(lm_lightintensityceiling)
 xx(lm_lightdistanceceiling)
+xx(lm_sampledist_line)
+xx(lm_sampledist_top)
+xx(lm_sampledist_mid)
+xx(lm_sampledist_bot)
+xx(lm_sampledist_floor)
+xx(lm_sampledist_ceiling)
 xx(lm_suncolor)
 xx(lm_sampledistance)
 xx(lm_gridsize)