diff --git a/lucene/test-framework/src/java/org/apache/lucene/util/LuceneTestCase.java b/lucene/test-framework/src/java/org/apache/lucene/util/LuceneTestCase.java
index e9a20f68c0c..2e1166eabea 100644
--- a/lucene/test-framework/src/java/org/apache/lucene/util/LuceneTestCase.java
+++ b/lucene/test-framework/src/java/org/apache/lucene/util/LuceneTestCase.java
@@ -1095,7 +1095,7 @@ public abstract class LuceneTestCase extends Assert {
     if (rarely(r)) {
       logmp.setMergeFactor(TestUtil.nextInt(r, 2, 9));
     } else {
-      logmp.setMergeFactor(TestUtil.nextInt(r, 100, 500));
+      logmp.setMergeFactor(TestUtil.nextInt(r, 10, 50));
     }
     configureRandom(r, logmp);
     return logmp;