diff --git a/.gitignore b/.gitignore
index d47c225..7b068e4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -229,6 +229,13 @@
 /lib/js/dist
 /lib/js/doc
 /lib/js/test/build
+/lib/kotlin/cross-test-client/build/
+/lib/kotlin/cross-test-server/build/
+/lib/kotlin/build/
+/lib/kotlin/.gradle/
+/lib/kotlin/gradle/
+/lib/kotlin/gradlew
+/lib/kotlin/gradlew.bat
 /lib/netstd/**/bin
 /lib/netstd/**/obj
 /lib/nodejs/coverage