diff --git a/libraries/stdlib/src/kotlin/text/Strings.kt b/libraries/stdlib/src/kotlin/text/Strings.kt
index 8eed2b07a56..8d3a39e4b67 100644
--- a/libraries/stdlib/src/kotlin/text/Strings.kt
+++ b/libraries/stdlib/src/kotlin/text/Strings.kt
@@ -189,7 +189,7 @@ public fun String?.isNullOrBlank(): Boolean = this == null || this.isBlank()
 /**
  * Iterator for characters of given CharSequence.
  */
-public fun CharSequence.iterator(): CharIterator = object : CharIterator() {
+public operator fun CharSequence.iterator(): CharIterator = object : CharIterator() {
     private var index = 0
 
     public override fun nextChar(): Char = get(index++)