diff --git a/python/educational-core/build.gradle b/python/educational-core/build.gradle
index b318fdfae640..d5fc71e721d9 100644
--- a/python/educational-core/build.gradle
+++ b/python/educational-core/build.gradle
@@ -25,6 +25,7 @@ subprojects {
   sourceSets {
     main {
       java.srcDir 'src'
+      kotlin.srcDirs 'src'
       resources.srcDir 'resources'
     }
     test {