diff --git a/bindings/bdk-kotlin/demo/build.gradle b/bindings/bdk-kotlin/demo/build.gradle
index 191a764..b320d2f 100644
--- a/bindings/bdk-kotlin/demo/build.gradle
+++ b/bindings/bdk-kotlin/demo/build.gradle
@@ -28,7 +28,7 @@ compileTestKotlin {
 }
 
 application {
-    mainClassName = 'MainKt'
+    mainClass.set('MainKt')
 }
 
 run {