1 files changed, 1 insertions, 1 deletions
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/container/PlatformBundles.java b/config-model/src/main/java/com/yahoo/vespa/model/container/PlatformBundles.java
index baa9c4b9a48..9f91f6bf5e1 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/container/PlatformBundles.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/container/PlatformBundles.java
@@ -69,7 +69,7 @@ public class PlatformBundles {
     private static Set<Path> toBundlePaths(String... bundleNames) {
         return Stream.of(bundleNames)
                 .map(PlatformBundles::absoluteBundlePath)
-                .collect(Collectors.toSet());
+                .collect(Collectors.toUnmodifiableSet());
     }
 
     public static Path absoluteBundlePath(String fileName) {