diff --git a/solr/core/src/java/org/apache/solr/update/UpdateLog.java b/solr/core/src/java/org/apache/solr/update/UpdateLog.java
index 4b6f7c290fb..2f55e407f90 100644
--- a/solr/core/src/java/org/apache/solr/update/UpdateLog.java
+++ b/solr/core/src/java/org/apache/solr/update/UpdateLog.java
@@ -1440,7 +1440,7 @@ public class UpdateLog implements PluginInfoInitialized {
             loglog.warn("REPLAY_ERR: Exception replaying log", ex);
             // something wrong with the request?
           }
-          TestInjection.injectUpdateLogReplayRandomPause();
+          assert TestInjection.injectUpdateLogReplayRandomPause();
         }
 
         CommitUpdateCommand cmd = new CommitUpdateCommand(req, false);