diff --git a/libraries/stdlib/js-ir/runtime/charSequence.kt b/libraries/stdlib/js-ir/runtime/charSequence.kt
index d59d7db3c56..f0766e33e1b 100644
--- a/libraries/stdlib/js-ir/runtime/charSequence.kt
+++ b/libraries/stdlib/js-ir/runtime/charSequence.kt
@@ -21,7 +21,7 @@ internal fun charSequenceGet(a: CharSequence, index: Int): Char {
 @DoNotIntrinsify
 internal fun charSequenceLength(a: CharSequence): Int {
     return if (isString(a)) {
-        js("a.length").unsafeCast<Int>()
+        a.asDynamic().length.unsafeCast<Int>()
     } else {
         a.length
     }