diff --git a/collects/tests/mzscheme/optimize.ss b/collects/tests/mzscheme/optimize.ss
index 97021bb871..cd7c4bf94d 100644
--- a/collects/tests/mzscheme/optimize.ss
+++ b/collects/tests/mzscheme/optimize.ss
@@ -402,6 +402,13 @@
 	      (f y))
 	   '11)
 
+(test-comp '(module m mzscheme
+              (define (f x) (+ x 1))
+              (f 8))
+	   '(module m mzscheme
+              (define (f x) (+ x 1))
+              9))
+
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;; Check bytecode verification of lifted functions
 
@@ -429,4 +436,14 @@
 
 ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
+;; Make sure "mutated?" flag isn't confused with "ready" flag:
+(module bad-order mzscheme  
+  (define (f) (printf "~a\n" i))
+  (f)
+  (define i 9)
+  (set! i 10))
+(err/rt-test (dynamic-require 'bad-order #f))
+
+;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
 (report-errs)
diff --git a/src/mzscheme/src/env.c b/src/mzscheme/src/env.c
index 2751837087..148b8317b6 100644
--- a/src/mzscheme/src/env.c
+++ b/src/mzscheme/src/env.c
@@ -3220,7 +3220,7 @@ Scheme_Object *scheme_resolve_toplevel(Resolve_Info *info, Scheme_Object *expr)
   return make_toplevel(skip + SCHEME_TOPLEVEL_DEPTH(expr), /* depth is 0 (normal) or 1 (exp-time) */
 		       SCHEME_TOPLEVEL_POS(expr),
 		       1,
-		       SCHEME_TOPLEVEL_FLAGS(expr) & SCHEME_TOPLEVEL_FLAGS_MASK);
+		       SCHEME_TOPLEVEL_FLAGS(expr) & SCHEME_TOPLEVEL_CONST);
 }
 
 Scheme_Object *scheme_shift_toplevel(Scheme_Object *expr, int delta)