diff --git a/libnetutil/netutil.cc b/libnetutil/netutil.cc
index e375060a9..3167c668d 100644
--- a/libnetutil/netutil.cc
+++ b/libnetutil/netutil.cc
@@ -1310,7 +1310,7 @@ int devname2ipaddr(char *dev, struct in_addr *addr) {
 /* Looks for an interface with the given name (iname), and returns the
    corresponding interface_info if found.  Will accept a match of
    devname or devfullname.  Returns NULL if none found */
-struct interface_info *getInterfaceByName(char *iname) {
+struct interface_info *getInterfaceByName(const char *iname) {
   struct interface_info *ifaces;
   int numifaces = 0;
   int ifnum;
diff --git a/libnetutil/netutil.h b/libnetutil/netutil.h
index 3e5837982..5e5b55f89 100644
--- a/libnetutil/netutil.h
+++ b/libnetutil/netutil.h
@@ -320,7 +320,7 @@ struct dnet_collector_route_nfo {
 /* Looks for an interface with the given name (iname), and returns the
    corresponding interface_info if found.  Will accept a match of
    devname or devfullname.  Returns NULL if none found */
-struct interface_info *getInterfaceByName(char *iname);
+struct interface_info *getInterfaceByName(const char *iname);
 
 /* Parse the system routing table, converting each route into a
    sys_route entry.  Returns an array of sys_routes.  numroutes is set