diff --git a/collects/mztake/debug-tool.ss b/collects/mztake/debug-tool.ss
index 82420080b9..3a6509ef06 100644
--- a/collects/mztake/debug-tool.ss
+++ b/collects/mztake/debug-tool.ss
@@ -483,7 +483,8 @@
                                                 (let loop ([i 0])
                                                   (when (< i (syntax-span bound))
                                                     (vector-set! pos-vec (+ i (syntax-position bound)) binding)
-                                                    (loop (add1 i))))))])
+                                                    (loop (add1 i)))))
+					      void)])
                                 (for-each (lambda (posn) (hash-table-put! breakpoints posn #f)) break-posns)
                                 ;(display-results (list orig-exp))
                                 annotated))))]))))))