diff --git a/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/Expression.kt b/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/Expression.kt
index c53d64871..19f4eeffd 100644
--- a/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/Expression.kt
+++ b/kmath-core/src/commonMain/kotlin/kscience/kmath/expressions/Expression.kt
@@ -95,7 +95,7 @@ public fun <T, E> ExpressionAlgebra<T, E>.bind(symbol: Symbol): E =
 /**
  * A delegate to create a symbol with a string identity in this scope
  */
-public val symbol: ReadOnlyProperty<Any?, Symbol>  = ReadOnlyProperty { thisRef, property ->
+public val symbol: ReadOnlyProperty<Any?, Symbol>  = ReadOnlyProperty { _, property ->
     StringSymbol(property.name)
 }