diff --git a/nwtests.c b/nwtests.c
index 607b17d..3fb3b97 100644
--- a/nwtests.c
+++ b/nwtests.c
@@ -1518,6 +1518,53 @@ static int tests_c32openref(int argc, char *argv[])
 }
 
 
+static int tests_c32mapconn_value(UI conn16, UI label)
+{
+  uint8 regs[16];
+  uint8 reply[128];
+  int rc;
+
+  memset(regs, 0, sizeof(regs));
+  memset(reply, 0, sizeof(reply));
+
+  /*
+   * Exact first half of __C32MapConn16To32:
+   *   reg.CX = conn16
+   *   reg.ES:DI = reply buffer
+   *   NWCVLMREQ(flags=2, regblk, p1=0Dh, p2=10h, p3=0)
+   */
+  tests_set_reg_word(regs, 4, FP_OFF(reply));  /* DI */
+  tests_set_reg_word(regs, 6, FP_SEG(reply));  /* ES */
+  tests_set_reg_word(regs, 12, conn16);        /* CX */
+
+  fprintf(stdout, "\nC32MAPCONN value=%u label=%u\n", conn16, label);
+  tests_dump_vlm_regs("REG in :", regs);
+  fprintf(stdout, "Call NWCVLMREQ flags=2 p1=000D p2=0010 p3=0000\n");
+
+  rc = Net_Call_NWCVLMREQ(2, regs, 0x000D, 0x0010, 0);
+
+  fprintf(stdout, "NWCVLMREQ rc=%04X\n", rc);
+  tests_dump_vlm_regs("REG out:", regs);
+  tests_dump_bytes("REPLY:", reply, 64);
+  fprintf(stdout, "REPLY text: %s\n", reply);
+
+  return rc;
+}
+
+static int tests_c32mapconnone(int argc, char *argv[])
+{
+  UI val;
+
+  if (argc < 3) {
+    fprintf(stdout, "Usage: TESTS C32MAPCONNONE value\n");
+    return(1);
+  }
+
+  val = (UI)atoi(argv[2]);
+  return tests_c32mapconn_value(val, val);
+}
+
+
 int func_tests(int argc, char *argv[], int mode)
 {
   if (argc >= 2) {
@@ -1548,6 +1595,9 @@ int func_tests(int argc, char *argv[], int mode)
     if (tests_same_arg(argv[1], "C32OPENREF"))
       return tests_c32openref(argc, argv);
 
+    if (tests_same_arg(argv[1], "C32MAPCONNONE"))
+      return tests_c32mapconnone(argc, argv);
+
     if (tests_same_arg(argv[1], "NWREQ87C32MATRIX"))
       return tests_nwreq87c32matrix();