diff --git a/src/google/protobuf/compiler/java/message.cc b/src/google/protobuf/compiler/java/message.cc
index 55f486e3ee..af64911e97 100644
--- a/src/google/protobuf/compiler/java/message.cc
+++ b/src/google/protobuf/compiler/java/message.cc
@@ -1624,7 +1624,7 @@ void ImmutableMessageGenerator::GenerateKotlinExtensions(
   printer->Print(
       "@kotlin.jvm.JvmSynthetic\n"
       "@Suppress(\"NOTHING_TO_INLINE\")\n"
-      "inline operator fun <T : com.google.protobuf.MessageLite> set(\n"
+      "public inline operator fun <T : com.google.protobuf.MessageLite> set(\n"
       "  extension: com.google.protobuf.ExtensionLite<$message$, T>,\n"
       "  value: T\n"
       ") {\n"