diff --git a/os2.rkt b/os2.rkt
index 7fbb0cb..b500cdf 100644
--- a/os2.rkt
+++ b/os2.rkt
@@ -238,24 +238,30 @@
 (define (make-send-message body [role 'publisher]) (send-message body role))
 (define (make-kill [pid #f] #:reason [reason #f]) (kill pid reason))
 
-(define (make-spawn main [k #f]
+(define (make-spawn raw-spec [k #f]
 		    #:monitor? [monitor? #f]
 		    #:debug-name [debug-name #f]
 		    #:state-contract [state-contract any/c])
+  (match-define (boot-specification raw-main raw-contract)
+    (cond [(boot-specification? raw-spec) raw-spec]
+	  [else (boot-specification raw-spec any/c)]))
   (define maybe-monitored-main
     (if monitor?
-	(let ((unmonitored-main (if (procedure? main) main (lambda (self-pid) main))))
+	(let ((unmonitored-main (if (procedure? raw-main) raw-main (lambda (self-pid) raw-main))))
 	  (lambda (self-pid)
 	    (define m (monitor self-pid debug-name))
 	    (prefix-transition (unmonitored-main self-pid)
 	      (role (list 'canary m) (topic-publisher m) #:state state))))
-	main))
+	raw-main))
+  (define final-contract
+    (cond [(eq? raw-contract any/c) state-contract]
+	  [(eq? state-contract any/c) raw-contract]
+	  [else (error 'spawn
+		       "Cannot apply #:state-contract to already-contracted boot-specification")]))
   (define spec
-    (if (eq? state-contract any/c)
-	main
-	(if (boot-specification? main)
-	    (error 'spawn "Cannot apply #:state-contract to already-contracted boot-specification")
-	    (boot-specification main state-contract))))
+    (if (eq? final-contract any/c)
+	maybe-monitored-main
+	(boot-specification maybe-monitored-main final-contract)))
   (spawn spec k debug-name))
 
 (define (extend-transition t . more-actions)