diff --git a/ConfigureChecks.cmake b/ConfigureChecks.cmake
index 01d4b745bd..4e2f0a01d0 100644
--- a/ConfigureChecks.cmake
+++ b/ConfigureChecks.cmake
@@ -108,7 +108,6 @@ if(HAVE_GETOPT_LONG)
 		check_symbol_exists("optreset"           HAVE_OPTRESET)
 	endif()
 endif()
-check_function_exists("getprotobynumber" HAVE_GETPROTOBYNUMBER)
 check_function_exists("getifaddrs"       HAVE_GETIFADDRS)
 check_function_exists("issetugid"        HAVE_ISSETUGID)
 check_function_exists("mkdtemp"          HAVE_MKDTEMP)
diff --git a/cmakeconfig.h.in b/cmakeconfig.h.in
index 085dbc3a64..ec715cef29 100644
--- a/cmakeconfig.h.in
+++ b/cmakeconfig.h.in
@@ -95,9 +95,6 @@
 /* Define to 1 if you have the <getopt.h> header file. */
 #cmakedefine HAVE_GETOPT_H 1
 
-/* Define to 1 if you have the `getprotobynumber' function. */
-#cmakedefine HAVE_GETPROTOBYNUMBER 1
-
 /* Define to 1 if you have the <grp.h> header file. */
 #cmakedefine HAVE_GRP_H 1
 
diff --git a/configure.ac b/configure.ac
index e13496cf92..6147d0898b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2347,7 +2347,6 @@ AC_REPLACE_FUNCS(strptime)
 AC_REPLACE_FUNCS(popcount)
 
 AC_CHECK_FUNCS(mkstemps mkdtemp)
-AC_CHECK_FUNCS(getprotobynumber)
 AC_CHECK_FUNCS(issetugid)
 AC_CHECK_FUNCS(sysconf)
 AC_CHECK_FUNCS(getifaddrs)
diff --git a/epan/ipproto.c b/epan/ipproto.c
index f328bf504a..97ed2d8c20 100644
--- a/epan/ipproto.c
+++ b/epan/ipproto.c
@@ -269,31 +269,7 @@ static const value_string ipproto_val[] = {
 value_string_ext ipproto_val_ext = VALUE_STRING_EXT_INIT(ipproto_val);
 
 const char *ipprotostr(const int proto) {
-    const char *s;
-
-    if ((s = try_val_to_str_ext(proto, &ipproto_val_ext)) != NULL)
-    return s;
-
-    s = "Unknown";
-
-#ifdef HAVE_GETPROTOBYNUMBER
-    /*
-     * XXX - have another flag for resolving network-layer
-     * protocol names?
-     */
-    if (gbl_resolv_flags.mac_name || gbl_resolv_flags.network_name ||
-        gbl_resolv_flags.transport_name) {
-        static char buf[128];
-        struct protoent *pe;
-
-    pe = getprotobynumber(proto);
-    if (pe) {
-        g_strlcpy(buf, pe->p_name, sizeof(buf));
-        s = buf;
-    }
-    }
-#endif
-    return s;
+    return val_to_str_ext_const(proto, &ipproto_val_ext, "Unknown");
 }
 
 /* https://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xhtml#extension-header */