diff --git a/tests/stdlib/tcstring.nim b/tests/stdlib/tcstring.nim
new file mode 100644
index 0000000000..2999251190
--- /dev/null
+++ b/tests/stdlib/tcstring.nim
@@ -0,0 +1,19 @@
+discard """
+  targets: "c cpp js"
+"""
+
+
+block: # bug #13859
+  let str = "abc".cstring
+  doAssert len(str).int8 == 3
+  doAssert len(str).int16 == 3
+  doAssert len(str).int32 == 3
+  var str2 = "cde".cstring
+  doAssert len(str2).int8 == 3
+  doAssert len(str2).int16 == 3
+  doAssert len(str2).int32 == 3
+
+  const str3 = "abc".cstring
+  doAssert len(str3).int32 == 3
+  doAssert len("abc".cstring).int16 == 3
+  doAssert len("abc".cstring).float32 == 3.0