diff --git a/slsSupportLib/include/network_utils.h b/slsSupportLib/include/network_utils.h
index f91472acd..12bc4a125 100755
--- a/slsSupportLib/include/network_utils.h
+++ b/slsSupportLib/include/network_utils.h
@@ -60,7 +60,7 @@ class MacAddr {
 
 IpAddr HostnameToIp(const char *hostname);
 std::string IpToInterfaceName(const std::string& ip);
-MacAddr InterfaceNameToMac(std::string inf);
+MacAddr InterfaceNameToMac(const std::string& inf);
 
 std::ostream &operator<<(std::ostream &out, const IpAddr &addr);
 std::ostream &operator<<(std::ostream &out, const MacAddr &addr);
diff --git a/slsSupportLib/src/network_utils.cpp b/slsSupportLib/src/network_utils.cpp
index d930bec32..98637cb03 100755
--- a/slsSupportLib/src/network_utils.cpp
+++ b/slsSupportLib/src/network_utils.cpp
@@ -122,7 +122,7 @@ std::string IpToInterfaceName(const std::string &ip) {
     return std::string(buf);
 }
 
-MacAddr InterfaceNameToMac(std::string inf) {
+MacAddr InterfaceNameToMac(const std::string& inf) {
         //TODO! Copied from genericSocket needs to be refactored!
 		struct ifreq ifr;
 		char mac[32];