diff --git a/collects/mzlib/private/unitidmap.ss b/collects/mzlib/private/unitidmap.ss
index 7a1bcca..a0eb58b 100644
--- a/collects/mzlib/private/unitidmap.ss
+++ b/collects/mzlib/private/unitidmap.ss
@@ -3,6 +3,9 @@
 
   ;; Help Desk binding info:
   (define (binding binder bound stx)
+    stx
+    ;; This 'bound-in-source is no longer needed
+    #;
     (syntax-property
      stx
      'bound-in-source
diff --git a/collects/mzlib/unit.ss b/collects/mzlib/unit.ss
index 113f1dd..801e4bb 100644
--- a/collects/mzlib/unit.ss
+++ b/collects/mzlib/unit.ss
@@ -119,7 +119,9 @@
 				       #f
 				       "bad syntax (illegal use of `.')"
 				       defn-or-expr))
-				    (expand-all l))]
+				    (expand-all (map (lambda (s)
+						       (syntax-track-origin s defn-or-expr #'begin))
+						     l)))]
 				 [else (list defn-or-expr)]))
 			     expanded))))])
 	       (let ([all-expanded (expand-all (syntax->list (syntax (defn&expr ...))))])