diff --git a/examples/server/utils.hpp b/examples/server/utils.hpp
index f73ec441f..79928264b 100644
--- a/examples/server/utils.hpp
+++ b/examples/server/utils.hpp
@@ -616,7 +616,7 @@ static json format_error_response(const std::string & message, const enum error_
     };
 }
 
-void from_json(const json& j, llama_control_vector_load_info& l) {
+static void from_json(const json& j, llama_control_vector_load_info& l) {
   j.at("strength").get_to(l.strength);
   j.at("fname").get_to(l.fname);
 }