diff --git a/src/headers/transpiler/Target.hpp b/src/headers/transpiler/Target.hpp
index 3ff70cc..ddbc655 100644
--- a/src/headers/transpiler/Target.hpp
+++ b/src/headers/transpiler/Target.hpp
@@ -167,7 +167,7 @@ unique_ptr<Target> Target::forName(string_view name, const bool newLines = true)
     #undef make_task
     #undef make_task_base_R
     #undef make_task_base
-    Yerbacon::fail({"\"", to_string(toupper(name.at(1))).data(), name.substr(2).data(), "\" is not a valid target."});
+    Yerbacon::fail({"\"", string(1, (char) toupper(name.at(1))).data(), name.substr(2).data(), "\" is not a valid target."});
     return nullptr;
 }