diff --git a/tools/utils/short-uuid_test.go b/tools/utils/short-uuid_test.go
index 3f9506588..8f20dbda0 100644
--- a/tools/utils/short-uuid_test.go
+++ b/tools/utils/short-uuid_test.go
@@ -8,6 +8,17 @@ import (
 )
 
 func TestShortUUID(t *testing.T) {
+	a, err := HumanUUID4()
+	if err != nil {
+		t.Fatal(err)
+	}
+	b, err := HumanUUID4()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if a == b {
+		t.Fatalf("Two short uuid4's are unexpectedly equal")
+	}
 	if HumanUUID.pad_to_length != 22 {
 		t.Fatalf("pad length for human UUID is %d not %d", HumanUUID.pad_to_length, 22)
 	}
@@ -19,8 +30,8 @@ func TestShortUUID(t *testing.T) {
 		t.Fatalf("uuid4 %s has unexpected length: %d", u, len(u))
 	}
 
-	b := big.NewInt(int64(1234567890123456789))
-	q := num_to_string(b, HumanUUID.alphabet, &HumanUUID.alphabet_len, HumanUUID.pad_to_length)
+	bi := big.NewInt(int64(1234567890123456789))
+	q := num_to_string(bi, HumanUUID.alphabet, &HumanUUID.alphabet_len, HumanUUID.pad_to_length)
 	const expected = "bzT6LtUjw4422222222222"
 	if q != expected {
 		t.Fatalf("unexpected short human serialization: %s != %s", q, expected)