diff --git a/oak-run-commons/src/main/java/org/apache/jackrabbit/oak/fixture/CompositeStoreFixture.java b/oak-run-commons/src/main/java/org/apache/jackrabbit/oak/fixture/CompositeStoreFixture.java
index fc09943bed..0e55da29bd 100644
--- a/oak-run-commons/src/main/java/org/apache/jackrabbit/oak/fixture/CompositeStoreFixture.java
+++ b/oak-run-commons/src/main/java/org/apache/jackrabbit/oak/fixture/CompositeStoreFixture.java
@@ -32,6 +32,7 @@ import org.apache.jackrabbit.oak.stats.StatisticsProvider;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.Arrays;
 
 import com.mongodb.MongoClientURI;
 
@@ -136,7 +137,7 @@ abstract class CompositeStoreFixture extends OakFixture {
             for (int j = 0; j < pathsPerMount; j++) {
                 paths[j] = String.format("/mount-%d-path-%d", i, j);
             }
-            mip.readOnlyMount("custom-mount-" + i, paths);
+            mip.mount("custom-mount-" + i, true, Arrays.asList("/oak:index"), Arrays.asList(paths));
         }
         CompositeNodeStore.Builder builder = new CompositeNodeStore.Builder(mip.build(), nodeStore);
         for (int i = 0; i < mounts; i++) {