diff --git a/test/val/bug1690.c b/test/val/bug1690.c
index 317913634..499dc6b35 100644
--- a/test/val/bug1690.c
+++ b/test/val/bug1690.c
@@ -2,22 +2,29 @@
 
 #include <stdio.h>
 
+static int failures = 0;
+static unsigned int z = 0xFF23;
+
 int main(void)
 {
     register unsigned int x = 0x200;
     register unsigned int y = 0;
 
-    do
-    {
+    do {
         ++y;
+    } while (--x);
+    if (y != 0x200) {
+        printf("y should be 0x200, not 0x%X.\n", y);
+        ++failures;;
     }
-    while (--x);
 
-    if (y != 0x200)
-	{
-		printf("0x%X\n", y);
-		return 1;
-	}
+    if ((z -= 0x23)) {
+        /* Passed -- non-zero z looks like non-zero. */
+    } else {
+        /* Failed -- only the low byte of z was tested. */
+        printf("Test thinks non-zero z is zero.\n");
+        ++failures;
+    }
 
-	return 0;
+    return failures;
 }