diff --git a/proto/compiler/.gitignore b/proto/compiler/.gitignore
index b0c44428b15..2cb7bf7d373 100644
--- a/proto/compiler/.gitignore
+++ b/proto/compiler/.gitignore
@@ -32,3 +32,10 @@ google/src/google/protobuf/*
 google/src/google/protobuf/compiler/*
 !google/src/google/protobuf/compiler/kotlin
 
+# Autogenerated protobuf artifacts for testing project
+google/src/google/protobuf/compiler/kotlin/protoc-tests/kt_js_tests/src/js_msg
+google/src/google/protobuf/compiler/kotlin/protoc-tests/kt_js_tests/src/kotlin_msg
+
+google/src/google/protobuf/compiler/kotlin/protoc-tests/kt_java_tests/src/java_msg
+google/src/google/protobuf/compiler/kotlin/protoc-tests/kt_java_tests/src/kotlin_msg
+