diff --git a/src/testlib/qtest.h b/src/testlib/qtest.h
index 9b8f12ec545..f3802d548b9 100644
--- a/src/testlib/qtest.h
+++ b/src/testlib/qtest.h
@@ -59,7 +59,7 @@ bool _q_compareSequence(ActualIterator actualIt, ActualIterator actualEnd,
                       "   Actual   (%s) size: %lld\n"
                       "   Expected (%s) size: %lld",
                       actual, qlonglong(actualSize),
-                  expected, expectedSize);
+                      expected, qlonglong(expectedSize));
     }
 
     for (auto expectedIt = expectedBegin; isOk && expectedIt < expectedEnd; ++actualIt, ++expectedIt) {