diff --git a/src/headers/misc.hpp b/src/headers/misc.hpp
index 4c145af..569692f 100644
--- a/src/headers/misc.hpp
+++ b/src/headers/misc.hpp
@@ -16,7 +16,7 @@ string getFileContent(const string& file);
 void setOutputFileContent(const string& language, const string& file, const string& content);
 
 #include "ParseComponents.hpp"
-ParseTree parseString(unique_ptr<string> toParse);
+ParseTree parseString(const unique_ptr<string>& toParse);
 string transpile(ParseTree toTranspile, string language);
 
 #endif //YERBACON_MISC_HPP
diff --git a/src/parser/MainParse.cpp b/src/parser/MainParse.cpp
index cc10d0a..f4cfca0 100644
--- a/src/parser/MainParse.cpp
+++ b/src/parser/MainParse.cpp
@@ -6,7 +6,7 @@
 
 using namespace std;
 
-ParseTree parseString(unique_ptr<string> toParse) {
+ParseTree parseString(const unique_ptr<string>& toParse) {
     ParseTree parseTree = ParseTree();
     auto lexed = lex(*toParse);
     for (tok& token: lexed) {