diff --git a/bgw-gui/src/jvmMain/kotlin/tools/aqua/bgw/util/BidirectionalMap.kt b/bgw-gui/src/jvmMain/kotlin/tools/aqua/bgw/util/BidirectionalMap.kt
index cc18d54fd..108af0a5c 100644
--- a/bgw-gui/src/jvmMain/kotlin/tools/aqua/bgw/util/BidirectionalMap.kt
+++ b/bgw-gui/src/jvmMain/kotlin/tools/aqua/bgw/util/BidirectionalMap.kt
@@ -99,7 +99,7 @@ open class BidirectionalMap<T : Any, R : Any>(vararg elements: Pair<T, R>) {
    *
    * @since 0.9
    */
-  operator fun get(it: T): Any {
+  operator fun get(it: T): R {
     if (containsForward(it)) return forward(it) else throw NoSuchElementException()
   }