diff --git a/collects/framework/private/color.rkt b/collects/framework/private/color.rkt
index fd576783..58d84c51 100644
--- a/collects/framework/private/color.rkt
+++ b/collects/framework/private/color.rkt
@@ -310,6 +310,7 @@ added get-regions
                                        (lexer-state-end-pos re-tokenize-ls-argument)
                                        (λ (x) #f)))
          (port-count-lines! re-tokenize-in-argument)
+         (set! rev (get-revision-number))
          (continue-re-tokenize start-time #t)]))
     
     (define re-tokenize-lses #f)
@@ -319,7 +320,8 @@ added get-regions
     (define re-tokenize-lexer-mode-argument #f)
     (define/private (continue-re-tokenize start-time did-something?)
       (cond
-        [(and did-something? ((+ start-time 20) . <= . (current-inexact-milliseconds)))
+        [(or (not (= rev (get-revision-number)))
+             (and did-something? ((+ start-time 20) . <= . (current-inexact-milliseconds))))
          #f]
         [else
          ;(define-values (_line1 _col1 pos-before) (port-next-location in))
@@ -512,7 +514,6 @@ added get-regions
             [(and colorer-pending? (= rev (get-revision-number)))
              (continue-re-tokenize (current-inexact-milliseconds) #f)]
             [else
-             (set! rev (get-revision-number))
              (start-re-tokenize (current-inexact-milliseconds))]))
         (cond
           [finished?