diff --git a/src/libexpr/value-to-xml.cc b/src/libexpr/value-to-xml.cc
index c3f352cfbd..e751fd300f 100644
--- a/src/libexpr/value-to-xml.cc
+++ b/src/libexpr/value-to-xml.cc
@@ -32,8 +32,10 @@ static void showAttrs(EvalState & state, bool strict, bool location,
     Bindings & attrs, XMLWriter & doc, PathSet & context, PathSet & drvsSeen)
 {
     StringSet names;
+    
     foreach (Bindings::iterator, i, attrs)
         names.insert(i->first);
+    
     foreach (StringSet::iterator, i, names) {
         Attr & a(attrs[state.symbols.create(*i)]);