diff --git a/lib/lib.pl b/lib/lib.pl
index 5fb09eac..f5502b96 100755
--- a/lib/lib.pl
+++ b/lib/lib.pl
@@ -36,6 +36,10 @@ print 'static void';
 print '_glibtop_missing_feature (glibtop *server, const char *feature,';
 print "\t\t\t  const u_int64_t present, u_int64_t *required)";
 print '{';
+print "\tu_int64_t old_required = *required;\n";
+print "\t/* Return if we have all required fields. */";
+print "\tif ((~present & old_required) == 0)";
+print "\t\treturn;\n";
 print "\tswitch (server->error_method) {";
 print "\tcase GLIBTOP_ERROR_METHOD_WARN_ONCE:";
 print "\t\t*required &= present;";
@@ -43,13 +47,13 @@ print "\tcase GLIBTOP_ERROR_METHOD_WARN:";
 print "\t\tglibtop_warn_r (server,";
 print "\t\t\t\t_(\"glibtop_get_%s (): Client requested \"";
 print "\t\t\t\t  \"field mask %05Lx, but only have %05Lx.\"),";
-print "\t\t\t\t feature, required, present);";
+print "\t\t\t\t feature, old_required, present);";
 print "\t\tbreak;";
 print "\tcase GLIBTOP_ERROR_METHOD_ABORT:";
 print "\t\tglibtop_error_r (server,";
 print "\t\t\t\t _(\"glibtop_get_%s (): Client requested \"";
 print "\t\t\t\t   \"field mask %05x, but only have %05x.\"),";
-print "\t\t\t\t feature, required, present);";
+print "\t\t\t\t feature, old_required, present);";
 print "\t\tbreak;";
 print "\t}";
 print '}';