diff --git a/selfdrive/common/util.h b/selfdrive/common/util.h
index 4edc15cd4c..adfcb4b91c 100644
--- a/selfdrive/common/util.h
+++ b/selfdrive/common/util.h
@@ -38,15 +38,15 @@ inline bool starts_with(const std::string &s, const std::string &prefix) {
   return s.compare(0, prefix.size(), prefix) == 0;
 }
 
-template<typename ... Args>
-inline std::string string_format( const std::string& format, Args ... args ) {
-    size_t size = snprintf( nullptr, 0, format.c_str(), args ... ) + 1;
-    std::unique_ptr<char[]> buf( new char[ size ] );
-    snprintf( buf.get(), size, format.c_str(), args ... );
-    return std::string( buf.get(), buf.get() + size - 1 );
+template <typename... Args>
+inline std::string string_format(const std::string& format, Args... args) {
+  size_t size = snprintf(nullptr, 0, format.c_str(), args...) + 1;
+  std::unique_ptr<char[]> buf(new char[size]);
+  snprintf(buf.get(), size, format.c_str(), args...);
+  return std::string(buf.get(), buf.get() + size - 1);
 }
 
-inline std::string read_file(std::string fn) {
+inline std::string read_file(const std::string &fn) {
   std::ifstream t(fn);
   std::stringstream buffer;
   buffer << t.rdbuf();