diff --git a/x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/index/store/SearchableSnapshotDirectoryStatsTests.java b/x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/index/store/SearchableSnapshotDirectoryStatsTests.java
index 8c662ec03cd..6ba2a6b4ec1 100644
--- a/x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/index/store/SearchableSnapshotDirectoryStatsTests.java
+++ b/x-pack/plugin/searchable-snapshots/src/test/java/org/elasticsearch/index/store/SearchableSnapshotDirectoryStatsTests.java
@@ -36,6 +36,7 @@ import static org.elasticsearch.index.store.cache.TestUtils.createCacheService;
 import static org.elasticsearch.index.store.cache.TestUtils.singleBlobContainer;
 import static org.elasticsearch.xpack.searchablesnapshots.SearchableSnapshots.SNAPSHOT_CACHE_ENABLED_SETTING;
 import static org.elasticsearch.xpack.searchablesnapshots.SearchableSnapshots.SNAPSHOT_UNCACHED_CHUNK_SIZE_SETTING;
+import static org.hamcrest.Matchers.allOf;
 import static org.hamcrest.Matchers.equalTo;
 import static org.hamcrest.Matchers.greaterThan;
 import static org.hamcrest.Matchers.greaterThanOrEqualTo;
@@ -117,7 +118,13 @@ public class SearchableSnapshotDirectoryStatsTests extends ESIndexInputTestCase
                 );
                 assertThat(
                     inputStats.getCachedBytesWritten().totalNanoseconds(),
-                    equalTo(cachedBytesWriteCount * FAKE_CLOCK_ADVANCE_NANOS)
+                    allOf(
+                        // each read takes at least FAKE_CLOCK_ADVANCE_NANOS time
+                        greaterThanOrEqualTo(FAKE_CLOCK_ADVANCE_NANOS * cachedBytesWriteCount),
+
+                        // worst case: we start all reads before finishing any of them
+                        lessThanOrEqualTo(FAKE_CLOCK_ADVANCE_NANOS * cachedBytesWriteCount * cachedBytesWriteCount)
+                    )
                 );
 
                 assertThat(inputStats.getCachedBytesRead(), notNullValue());