diff --git a/tests/js/t16726.nim b/tests/js/t16726.nim
new file mode 100644
index 0000000000..bd28af4cd0
--- /dev/null
+++ b/tests/js/t16726.nim
@@ -0,0 +1,9 @@
+discard """
+  errormsg: "type mismatch"
+"""
+
+# issue #16726
+# the code below should give a clean CT error, not an internal error
+import std/jsffi
+let a = toJs(3)
+let b = a.toJs(int)