diff --git a/src/scripting/game_lua_kernel.cpp b/src/scripting/game_lua_kernel.cpp
index 9e7f7e1d426..083ece2d558 100644
--- a/src/scripting/game_lua_kernel.cpp
+++ b/src/scripting/game_lua_kernel.cpp
@@ -3278,6 +3278,7 @@ static int intf_add_modification(lua_State *L)
 	std::string sm = m;
 	if (sm == "advance") { // Maintain backwards compatibility
 		sm = "advancement";
+		lg::wml_error << "(Lua) Modifications of type \"advance\" are deprecated, use \"advancement\" instead\n";
 	}
 	if (sm != "advancement" && sm != "object" && sm != "trait") {
 		return luaL_argerror(L, 2, "unknown modification type");
diff --git a/src/unit.cpp b/src/unit.cpp
index b34b2d03cf8..4e8fbfb3bc6 100644
--- a/src/unit.cpp
+++ b/src/unit.cpp
@@ -2069,6 +2069,9 @@ void unit::apply_modifications()
 
 	for(size_t i = 0; i != NumModificationTypes; ++i) {
 		const std::string& mod = ModificationTypes[i];
+		if(mod == "advance" && modifications_.has_child(mod)) {
+			lg::wml_error << "[modifications][advance] is deprecated, use [advancement] instead\n";
+		}
 		BOOST_FOREACH(const config &m, modifications_.child_range(mod)) {
 			log_scope("add mod");
 			add_modification(ModificationTypes[i], m, true);