diff --git a/src/swish/http.ms b/src/swish/http.ms
index ba595c31..a59633d9 100644
--- a/src/swish/http.ms
+++ b/src/swish/http.ms
@@ -776,7 +776,7 @@
   (let-values ([(ip op) (connect-tcp "127.0.0.1" (get-http-port))])
     (put-bytevector op (string->utf8 "Malformed Request\r\n\r\n"))
     (flush-output-port op)
-    (receive (after 10 (throw 'no-child-log))
+    (test:receive (after 10 (throw 'no-child-log))
       [`(<child-end> [reason #(http-unhandled-input ,x)])
        (assert (string=? (utf8->string x) "Malformed Request"))])
     (close-port op))
@@ -792,7 +792,7 @@
       (spawn&link
        (lambda ()
          (send me `#(read ,(utf8->string (get-bytevector-all ip)))))))
-    (receive (after 100 (throw 'timeout))
+    (test:receive (after 100 (throw 'timeout))
       [#(read ,x)
        (unless (string=? x
                  (string-append
@@ -807,7 +807,7 @@
         [fail-msg `#(accept-tcp-failed "listener" "who" "errno")])
     (link http)
     (send http fail-msg)
-    (receive (after 100 (throw 'timeout))
+    (test:receive (after 100 (throw 'timeout))
       [`(EXIT ,@http ,@fail-msg) 'ok])))
 
 (http-mat http-respond ()
@@ -1058,7 +1058,7 @@
           (match ls
             [() 'ok]
             [(,n . ,rest)
-             (receive (after 100 (throw `#(failed-to-read-data ,n)))
+             (test:receive (after 100 (throw `#(failed-to-read-data ,n)))
                [#(read ,@n) (lp rest)])])))
 
       (check-loopback '(9 8 7 6 5))
@@ -1387,14 +1387,14 @@
         (send pid msg)
         (check c s)))
     (define (check-crash c s)
-      (receive (after 100 (throw 'no-client-close))
+      (test:receive (after 100 (throw 'no-client-close))
         [#(ws:closed ,@c 1011 "") 'ok])
-      (receive (after 100 (throw 'no-child-log))
+      (test:receive (after 100 (throw 'no-child-log))
         [`(<child-end> [pid ,@s] [reason crashed]) 'ok]))
     (define (check-normal c s)
-      (receive (after 100 (throw 'no-client-close))
+      (test:receive (after 100 (throw 'no-client-close))
         [#(ws:closed ,@c 1000 "") 'ok])
-      (receive (after 100 (throw 'no-child-log))
+      (test:receive (after 100 (throw 'no-child-log))
         [`(<child-end> [pid ,@s] [reason normal]) 'ok]))
     (do-test #f 'crash check-crash)
     (do-test #t 'crash check-crash)
diff --git a/src/swish/testing.ss b/src/swish/testing.ss
index 5e2fb0d4..1bb7141b 100644
--- a/src/swish/testing.ss
+++ b/src/swish/testing.ss
@@ -49,6 +49,7 @@
    start-event-mgr
    start-silent-event-mgr
    system-mat
+   test:receive
    )
   (import
    (chezscheme)
@@ -347,6 +348,30 @@
               [stderr (receive [#(stderr ,@os-pid ,lines) lines])]
               [exit-status exit-status])])))))
 
+  (define-syntax (test:receive x)
+    (define (en-guarde cl)
+      (syntax-case cl ()
+        [(pattern (guard g) b1 b2 ...)
+         (eq? (datum guard) 'guard)
+         cl]
+        [(pattern b1 b2 ...)
+         #'(pattern (guard #t) b1 b2 ...)]))
+    (syntax-case x ()
+      [(_ (after timeout t1 t2 ...) clause ...)
+       (and (eq? (datum after) 'after) (getenv "TIMEOUT_SCALE_FACTOR"))
+       (with-syntax ([(quote #(at offset fn)) (find-source x)]
+                     [(n ...) (iota (length (datum (clause ...))))]
+                     [((pattern guard b1 b2 ...) ...)
+                      (map en-guarde #'(clause ...))])
+         #'(let* ([raw-timeout timeout]
+                  [start (erlang:now)])
+             (define (report where)
+               (fprintf (console-error-port) "hit clause ~s at ~a:~s after ~s ms [raw timeout ~s]\n"
+                 where fn offset (- (erlang:now) start) raw-timeout))
+             (receive (after (scale-timeout raw-timeout) (report 'timeout) t1 t2 ...)
+               [pattern guard (report n) b1 b2 ...] ...)))]
+      [(_ e ...) #'(receive e ...)]))
+
   (define (scale-timeout timeout)
     (define scale-factor
       (or (cond
@@ -547,5 +572,4 @@
               [() (getenv var)]
               [(x) (when (string? x) (putenv var x))])))
          ...)]))
-
   )