diff --git a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/PushOneCommit.java b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/PushOneCommit.java
index 6e86e34c2f..428a19cd62 100644
--- a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/PushOneCommit.java
+++ b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/PushOneCommit.java
@@ -258,9 +258,9 @@ public class PushOneCommit {
           .named("unexpected reviewer " + accountId)
           .isTrue();
       }
-      assertThat(expectedReviewerIds.isEmpty())
+      assertThat((Iterable<?>)expectedReviewerIds)
         .named("missing reviewers: " + expectedReviewerIds)
-        .isTrue();
+        .isEmpty();
     }
 
     public void assertOkStatus() {