diff --git a/src/lua_consolelib.c b/src/lua_consolelib.c
index 12a5f2ff3..84dfba083 100644
--- a/src/lua_consolelib.c
+++ b/src/lua_consolelib.c
@@ -543,7 +543,7 @@ static int cvar_get(lua_State *L)
 	else if(fastcmp(field,"changed"))
 		lua_pushboolean(L, cvar->changed);
 	else if (devparm)
-		return luaL_error(L, LUA_QL("consvar_t") " has no field named " LUA_QS, field);
+		return luaL_error(L, LUA_QL("consvar_t") " has no field named " LUA_QS ".", lua_tostring(L, 2));
 	else
 		return 0;
 	return 1;
diff --git a/src/lua_maplib.c b/src/lua_maplib.c
index e3ed007a3..abec45615 100644
--- a/src/lua_maplib.c
+++ b/src/lua_maplib.c
@@ -646,8 +646,9 @@ static int sector_set(lua_State *L)
 	case sector_ffloors: // ffloors
 	case sector_fslope: // f_slope
 	case sector_cslope: // c_slope
+		return luaL_error(L, "sector_t has no field named " LUA_QS ".", lua_tostring(L, 2));
 	default:
-		return luaL_error(L, "sector_t field " LUA_QS " cannot be set.", sector_opt[field]);
+		return luaL_error(L, "sector_t has no field named " LUA_QS ".", lua_tostring(L, 2));
 	case sector_floorheight: { // floorheight
 		boolean flag;
 		mobj_t *ptmthing = tmthing;
@@ -1022,8 +1023,9 @@ static int side_set(lua_State *L)
 	case side_sector:
 	case side_special:
 	case side_text:
-	default:
 		return luaL_error(L, "side_t field " LUA_QS " cannot be set.", side_opt[field]);
+	default:
+		return luaL_error(L, "side_t has no field named " LUA_QS ".", lua_tostring(L, 2));
 	case side_textureoffset:
 		side->textureoffset = luaL_checkfixed(L, 3);
 		break;
@@ -1839,8 +1841,9 @@ static int ffloor_set(lua_State *L)
 	case ffloor_target: // target
 	case ffloor_next: // next
 	case ffloor_prev: // prev
-	default:
 		return luaL_error(L, "ffloor_t field " LUA_QS " cannot be set.", ffloor_opt[field]);
+	default:
+		return luaL_error(L, "ffloor_t has no field named " LUA_QS ".", lua_tostring(L, 2));
 	case ffloor_topheight: { // topheight
 		boolean flag;
 		fixed_t lastpos = *ffloor->topheight;
@@ -1964,8 +1967,9 @@ static int slope_set(lua_State *L)
 	case slope_d: // d
 	case slope_flags: // flags
 	case slope_normal: // normal
-	default:
 		return luaL_error(L, "pslope_t field " LUA_QS " cannot be set.", slope_opt[field]);
+	default:
+		return luaL_error(L, "pslope_t has no field named " LUA_QS ".", lua_tostring(L, 2));
 	case slope_o: { // o
 		luaL_checktype(L, 3, LUA_TTABLE);