diff --git a/src/compiler/prepare_grammar/perform.cpp b/src/compiler/prepare_grammar/perform.cpp
index 6b388554..0b36b0b5 100644
--- a/src/compiler/prepare_grammar/perform.cpp
+++ b/src/compiler/prepare_grammar/perform.cpp
@@ -8,8 +8,7 @@ namespace tree_sitter {
     
     namespace prepare_grammar {
         pair<PreparedGrammar, PreparedGrammar> perform(const Grammar &input_grammar) {
-            PreparedGrammar grammar(input_grammar);
-            auto grammars = prepare_grammar::extract_tokens(grammar);
+            auto grammars = prepare_grammar::extract_tokens(input_grammar);
             auto rule_grammar = expand_repeats(grammars.first);
             auto lex_grammar = grammars.second;
             return { rule_grammar, lex_grammar };