diff --git a/types/tx_test.go b/types/tx_test.go
index 00ef29e14..dcd13f3f6 100644
--- a/types/tx_test.go
+++ b/types/tx_test.go
@@ -302,6 +302,6 @@ func assertBadProof(t *testing.T, root []byte, bad []byte, good TxProof) {
 }
 
 func randInt(low, high int) int {
-	off := rand.Int() % (high - low)
+	return rand.Intn(high-low) + low
 	return low + off
 }