diff --git a/nwtests.c b/nwtests.c
index 7ae8398..d994e79 100644
--- a/nwtests.c
+++ b/nwtests.c
@@ -302,23 +302,29 @@ static int tests_ncpf2(int argc, char *argv[])
 
 int func_tests(int argc, char *argv[], int mode)
 {
-  if (argc < 2)
-    return tests_old(argc, argv, mode);
+  if (argc >= 2) {
+    if (tests_same_arg(argv[1], "NETCALL"))
+      return tests_netcall();
 
-  if (tests_same_arg(argv[1], "NETCALL"))
-    return tests_netcall();
+    if (tests_same_arg(argv[1], "E300") || tests_same_arg(argv[1], "NETCALLE300"))
+      return tests_netcall_e300();
 
-  if (tests_same_arg(argv[1], "E300") || tests_same_arg(argv[1], "NETCALLE300"))
-    return tests_netcall_e300();
+    if (tests_same_arg(argv[1], "NCPF2"))
+      return tests_ncpf2(argc, argv);
 
-  if (tests_same_arg(argv[1], "OLD"))
-    return tests_old(argc - 1, argv + 1, mode);
+    if (tests_same_arg(argv[1], "OLD"))
+      return tests_old(argc - 1, argv + 1, mode);
 
-  if (tests_same_arg(argv[1], "/?") || tests_same_arg(argv[1], "-?") ||
-      tests_same_arg(argv[1], "?")) {
-    tests_usage();
-    return(0);
+    if (tests_same_arg(argv[1], "/?") || tests_same_arg(argv[1], "-?") ||
+        tests_same_arg(argv[1], "?")) {
+      tests_usage();
+      return(0);
+    }
   }
 
+  /*
+   * Default and unknown arguments keep the historical nwtests.c behavior.
+   */
   return tests_old(argc, argv, mode);
 }
+