diff --git a/ets2panda/lsp/src/isolated_declaration.cpp b/ets2panda/lsp/src/isolated_declaration.cpp
index 621b219c4125ce3b7a5cb26f28880366b63e10e5..d4df74d45d740538637ee4e4c4ff8bf89eeb1ca6 100644
--- a/ets2panda/lsp/src/isolated_declaration.cpp
+++ b/ets2panda/lsp/src/isolated_declaration.cpp
@@ -49,7 +49,8 @@ std::optional<std::string> GenUnionType(const checker::ETSUnionType *unionType,
                                         const char splitChar);
 
 template <class UnionType>
-std::vector<UnionType *> FilterUnionTypes(const ArenaVector<UnionType *> &originTypes, checker::ETSChecker *checker)
+std::vector<UnionType *> FilterUnionTypes(const ArenaVector<UnionType *> &originTypes,
+                                          [[maybe_unused]] checker::ETSChecker *checker)
 {
     if (originTypes.empty()) {
         return {};