diff --git a/src/engine/positioninfo.h b/src/engine/positioninfo.h
--- a/src/engine/positioninfo.h
+++ b/src/engine/positioninfo.h
@@ -47,7 +47,9 @@
 };
 
 inline QDebug operator<<(QDebug dbg, const PositionInfo &pos) {
-    dbg << "(" << pos.docId << "-->" << pos.positions << ")";
+    QDebugStateSaver saver(dbg);
+    dbg.nospace() << Qt::hex << "(" << pos.docId << ": "
+                  << Qt::dec << pos.positions << ")";
     return dbg;
 }