diff --git a/gnovm/pkg/gnolang/preprocess.go b/gnovm/pkg/gnolang/preprocess.go
index c86edb0e515..1d215e4d94b 100644
--- a/gnovm/pkg/gnolang/preprocess.go
+++ b/gnovm/pkg/gnolang/preprocess.go
@@ -978,11 +978,14 @@ func Preprocess(store Store, ctx BlockNode, n Node) Node {
 										arg0))
 								}
 							}
-
 							convertConst(store, last, arg0, ct)
 							constConverted = true
+						case SliceKind:
+							if ct.Elem().Kind() == Uint8Kind { // bypass []byte("xxx")
+								n.SetAttribute(ATTR_TYPEOF_VALUE, ct)
+								return n, TRANS_CONTINUE
+							}
 						}
-
 						// (const) untyped decimal -> float64.
 						// (const) untyped bigint -> int.
 						if !constConverted {
diff --git a/gnovm/tests/files/byte_slice_issue1570.gno b/gnovm/tests/files/byte_slice_issue1570.gno
new file mode 100644
index 00000000000..c1956f3d15d
--- /dev/null
+++ b/gnovm/tests/files/byte_slice_issue1570.gno
@@ -0,0 +1,15 @@
+package main
+
+func main() {
+	for i := 0; i < 2; i++ {
+		l := []byte("lead")
+		if i == 0 {
+			l[0] = 'f'
+		}
+		println(string(l))
+	}
+}
+
+// Output:
+// fead
+// lead