diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 8665edcfa..e6ea73efc 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -684,6 +684,9 @@ Expr strictEvalExpr(EvalState & state, Expr e, bool canonicalise)
             if (!matchBind(*i, name, e, pos)) abort(); /* can't happen */
             as2 = ATinsert(as2, makeBind(name, strictEvalExpr(state, e, canonicalise),
                                canonicalise ? makeNoPos() : pos));
+        }
+        if (canonicalise) {
+            
         }
         /* !!! sort attributes if canonicalise == true */
         return makeAttrs(ATreverse(as2));
@@ -716,6 +719,7 @@ Expr strictEvalExpr(EvalState & state, Expr e, bool canonicalise)
 
             formals2 = ATinsert(formals2, makeFormal(name, valids, dummy));
         }
+        
         return makeFunction(ATreverse(formals2), body,
             canonicalise ? makeNoPos() : pos);
     }
diff --git a/src/libexpr/expr-to-xml.cc b/src/libexpr/expr-to-xml.cc
index 5c5b81b23..1a7302df1 100644
--- a/src/libexpr/expr-to-xml.cc
+++ b/src/libexpr/expr-to-xml.cc
@@ -2,6 +2,7 @@
 #include "xml-writer.hh"
 #include "nixexpr-ast.hh"
 #include "aterm.hh"
+#include "util.hh"
 
 
 namespace nix {
@@ -24,6 +25,8 @@ static void printTermAsXML(Expr e, XMLWriter & doc, PathSet & context)
     ATermList as, es, formals;
     ATerm body, pos;
 
+    checkInterrupt();
+
     if (matchStr(e, s, context)) /* !!! show the context? */
         doc.writeEmptyElement("string", singletonAttrs("value", s));