diff --git a/collects/2htdp/private/img-err.rkt b/collects/2htdp/private/img-err.rkt
index e68488f185..19c57dca7c 100644
--- a/collects/2htdp/private/img-err.rkt
+++ b/collects/2htdp/private/img-err.rkt
@@ -282,11 +282,15 @@
             argname)]))
 
 (define (y-place? arg)
-  (member arg '("top" top "bottom" bottom "middle" middle "center" center "baseline" baseline "pinhole" pinhole)))
+  (and (member arg '("top" top "bottom" bottom "middle" middle "center" center 
+                           "baseline" baseline "pinhole" pinhole))
+       #t))
 (define (x-place? arg)
-  (member arg '("left" left "right" right "middle" middle "center" center "pinhole" pinhole)))
+  (and (member arg '("left" left "right" right "middle" middle
+                            "center" center "pinhole" pinhole))
+       #t))
 (define (mode? arg)
-  (or (member arg '(solid outline "solid" "outline"))
+  (or (and (member arg '(solid outline "solid" "outline")) #t)
       (and (integer? arg)
            (<= 0 arg 255))))
 (define (angle? arg)
@@ -300,14 +304,17 @@
        (1 . <= .  i)))
 (define (image-color? c) (or (symbol? c) (string? c) (color? c)))
 (define (pen-style? arg) 
-  (member (if (string? arg) (string->symbol arg) arg)
-          '(solid dot long-dash short-dash dot-dash)))
+  (and (member (if (string? arg) (string->symbol arg) arg)
+               '(solid dot long-dash short-dash dot-dash))
+       #t))
 (define (pen-cap? arg)
-  (member (if (string? arg) (string->symbol arg) arg)
-          '(round projecting butt)))
+  (and (member (if (string? arg) (string->symbol arg) arg)
+               '(round projecting butt))
+       #t))
 (define (pen-join? arg)
-  (member (if (string? arg) (string->symbol arg) arg)
-          '(round bevel miter)))
+  (and (member (if (string? arg) (string->symbol arg) arg)
+               '(round bevel miter))
+       #t))
 (define (real-valued-posn? arg)
   (and (posn? arg)
        (real? (posn-x arg))
diff --git a/collects/2htdp/tests/test-image.rkt b/collects/2htdp/tests/test-image.rkt
index 9b5225133a..17904833b9 100644
--- a/collects/2htdp/tests/test-image.rkt
+++ b/collects/2htdp/tests/test-image.rkt
@@ -120,6 +120,25 @@
           (map loop (cdr (vector->list (struct->vector x))))))]
       [else x])))
 
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;
+;; predicates
+;;
+
+(test (mode? "outline") => #t)
+(test (mode? 'outline) => #t)
+(test (mode? 'oooutlineh) => #f)
+(test (pen-style? 'solid) => #t)
+(test (pen-style? 'solidd) => #f)
+(test (pen-cap? 'round) => #t)
+(test (pen-cap? 'roound) => #f)
+(test (pen-join? 'round) => #t)
+(test (pen-join? 'roound) => #f)
+(test (x-place? 'left) => #t)
+(test (x-place? 'zuo) => #f)
+(test (y-place? 'top) => #t)
+(test (y-place? 'shang) => #f)
+
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 ;;
 ;; circle vs ellipse