diff --git a/libraries/tools/kotlin-stdlib-gen/src/templates/dsl/MemberBuilder.kt b/libraries/tools/kotlin-stdlib-gen/src/templates/dsl/MemberBuilder.kt
index 08173795e6c..caa91ecac51 100644
--- a/libraries/tools/kotlin-stdlib-gen/src/templates/dsl/MemberBuilder.kt
+++ b/libraries/tools/kotlin-stdlib-gen/src/templates/dsl/MemberBuilder.kt
@@ -66,7 +66,7 @@ class MemberBuilder(
     var returns: String? = null; private set
     val throwsExceptions = mutableListOf<ThrowsException>()
     var body: String? = null; private set
-    val annotations: MutableList<String> = mutableListOf()
+    val annotations: MutableSet<String> = mutableSetOf()
     val suppressions: MutableList<String> = mutableListOf()
 
     fun sourceFile(file: SourceFile) { sourceFile = file }