diff --git a/builtin/mainmenu/dlg_create_world.lua b/builtin/mainmenu/dlg_create_world.lua
index 30ec05fda..3f501d8ff 100644
--- a/builtin/mainmenu/dlg_create_world.lua
+++ b/builtin/mainmenu/dlg_create_world.lua
@@ -175,7 +175,8 @@ local function create_world_formspec(dialogdata)
 	if not is_internal_mapgen then
 		-- Select singlenode if using lua-defined mapgen
 		-- Here we have to make sure it doesn't override an internal mapgen
-		if lua_mapgens[current_mapgen_internal] ~= nil and (current_mapgen == dialogdata.mg or lua_mapgens[current_mapgen_internal].title == dialogdata.mg) then
+		if lua_mapgens[current_mapgen_internal] ~= nil and 
+			(current_mapgen == dialogdata.mg or lua_mapgens[current_mapgen_internal].title == dialogdata.mg) then
 			current_mapgen_internal = "singlenode"
 		end
 	end
diff --git a/src/content/mod_configuration.cpp b/src/content/mod_configuration.cpp
index 054952547..c50a3994a 100644
--- a/src/content/mod_configuration.cpp
+++ b/src/content/mod_configuration.cpp
@@ -132,17 +132,22 @@ void ModConfiguration::addMapgenFromConfig(
 	 *
 	 * If the mod is enabled, add it to `mapgen_mod` and break
 	 */
+	bool mapgen_found = false;
 	for (const auto &mapgenPath : mapgenPaths) {
 		std::vector<ModSpec> addon_mods_in_path = flattenMods(getModsInPath(mapgenPath.second, mapgenPath.first));
 		for (const auto &mod : addon_mods_in_path) {
 			if (mod.name == mapgen) {
 				mapgen_mod.push_back(mod);
+				mapgen_found = true;
 				break;
 			}
 		}
 	}
 
-	addMods(mapgen_mod);
+	if (!mapgen_found) {
+		throw ModError("This world is configured to use a lua-defined mapgen: '" + mapgen + "' must be installed to load this world.");
+	} else
+		addMods(mapgen_mod);
 }
 
 void ModConfiguration::addModsFromConfig(