diff --git a/lucene/core/src/test/org/apache/lucene/util/TestFixedBitSet.java b/lucene/core/src/test/org/apache/lucene/util/TestFixedBitSet.java
index 11cf4c0f705..280ec3eb3b4 100644
--- a/lucene/core/src/test/org/apache/lucene/util/TestFixedBitSet.java
+++ b/lucene/core/src/test/org/apache/lucene/util/TestFixedBitSet.java
@@ -456,9 +456,10 @@ public class TestFixedBitSet extends BaseBitSetTestCase<FixedBitSet> {
     int count1 = TestUtil.nextInt(random, 0, numBits1 - 1);
     int count2 = TestUtil.nextInt(random, 0, numBits2 - 1);
 
-    int offSetWord1 = FixedBitSet.bits2words(TestUtil.nextInt(random, 0, count1));
+    int min = TestUtil.nextInt(random, 0, numBits1 - 1);
+    int offSetWord1 = min >> 6;
     int offset1 = offSetWord1 << 6;
-    int[] bits1 = makeIntArray(random, count1, offset1, numBits1 - 1);
+    int[] bits1 = makeIntArray(random, count1, min, numBits1 - 1);
     int[] bits2 = makeIntArray(random, count2, 0, numBits2 - 1);
 
     java.util.BitSet bitSet1 = makeBitSet(bits1);