diff --git a/implementations/racket/preserves/main.rkt b/implementations/racket/preserves/main.rkt
index b3fcaa5..4698acd 100644
--- a/implementations/racket/preserves/main.rkt
+++ b/implementations/racket/preserves/main.rkt
@@ -143,44 +143,48 @@
   (encode-array-like 0 (cons key fields)))
 
 (define (encode-value v)
-  (match v
-    [#f (bytes #b00000000)]
-    [#t (bytes #b00000001)]
-    [(? single-flonum?) (bit-string #b00000010 (v :: float bits 32))]
-    [(? double-flonum?) (bit-string #b00000011 (v :: float bits 64))]
-    [(annotated annotations _ item)
-     (bit-string ((apply bit-string-append
-                         (map (lambda (a) (bit-string #b00000101 ((encode-value a) :: binary)))
-                              annotations)) :: binary)
-                 ((encode-value item) :: binary))]
-    [(stream-of 'string p)      (encode-stream 1 1 bytes? p)]
-    [(stream-of 'byte-string p) (encode-stream 1 2 bytes? p)]
-    [(stream-of 'symbol p)      (encode-stream 1 3 bytes? p)]
-    [(stream-of 'sequence p)    (encode-stream 2 1 (lambda (x) #t) p)]
-    [(stream-of 'set p)         (encode-stream 2 2 (lambda (x) #t) p)]
-    [(stream-of 'dictionary p)  (encode-stream 2 3 (lambda (x) #t) p)]
+  (match ((current-value->placeholder) v)
+    [(? integer? n)
+     (bit-string (#b0001 :: bits 4) (n :: (wire-length)))]
+    [#f
+     (match v
+       [#f (bytes #b00000000)]
+       [#t (bytes #b00000001)]
+       [(? single-flonum?) (bit-string #b00000010 (v :: float bits 32))]
+       [(? double-flonum?) (bit-string #b00000011 (v :: float bits 64))]
+       [(annotated annotations _ item)
+        (bit-string ((apply bit-string-append
+                            (map (lambda (a) (bit-string #b00000101 ((encode-value a) :: binary)))
+                                 annotations)) :: binary)
+                    ((encode-value item) :: binary))]
+       [(stream-of 'string p)      (encode-stream 1 1 bytes? p)]
+       [(stream-of 'byte-string p) (encode-stream 1 2 bytes? p)]
+       [(stream-of 'symbol p)      (encode-stream 1 3 bytes? p)]
+       [(stream-of 'sequence p)    (encode-stream 2 1 (lambda (x) #t) p)]
+       [(stream-of 'set p)         (encode-stream 2 2 (lambda (x) #t) p)]
+       [(stream-of 'dictionary p)  (encode-stream 2 3 (lambda (x) #t) p)]
 
-    [(? integer? x) #:when (<= -3 x 12) (bit-string (#b0011 :: bits 4) (x :: bits 4))]
-    ;; [0 (bytes #b10000000)]
-    [(? integer?)
-     (define raw-bit-count (+ (integer-length v) 1)) ;; at least one sign bit
-     (define byte-count (quotient (+ raw-bit-count 7) 8))
-     (bit-string (#b0100 :: bits 4) (byte-count :: (wire-length)) (v :: integer bytes byte-count))]
-    [(? string?) (encode-binary-like 1 (string->bytes/utf-8 v))]
-    [(? bytes?)  (encode-binary-like 2 v)]
-    [(? symbol?) (encode-binary-like 3 (string->bytes/utf-8 (symbol->string v)))]
+       [(? integer? x) #:when (<= -3 x 12) (bit-string (#b0011 :: bits 4) (x :: bits 4))]
+       ;; [0 (bytes #b10000000)]
+       [(? integer?)
+        (define raw-bit-count (+ (integer-length v) 1)) ;; at least one sign bit
+        (define byte-count (quotient (+ raw-bit-count 7) 8))
+        (bit-string (#b0100 :: bits 4) (byte-count :: (wire-length)) (v :: integer bytes byte-count))]
+       [(? string?) (encode-binary-like 1 (string->bytes/utf-8 v))]
+       [(? bytes?)  (encode-binary-like 2 v)]
+       [(? symbol?) (encode-binary-like 3 (string->bytes/utf-8 (symbol->string v)))]
 
-    [(record label fields) (encode-record label fields)]
-    [(? non-object-struct?)
-     (define key (prefab-struct-key v))
-     (when (not key) (error 'encode-value "Cannot encode non-prefab struct ~v" v))
-     (encode-record key (cdr (vector->list (struct->vector v))))]
+       [(record label fields) (encode-record label fields)]
+       [(? non-object-struct?)
+        (define key (prefab-struct-key v))
+        (when (not key) (error 'encode-value "Cannot encode non-prefab struct ~v" v))
+        (encode-record key (cdr (vector->list (struct->vector v))))]
 
-    [(? list?)   (encode-array-like 1 v)]
-    [(? set?)    (encode-array-like 2 (set->list v))]
-    [(? dict?)   (encode-array-like 3 (dict-keys-and-values v))]
+       [(? list?)   (encode-array-like 1 v)]
+       [(? set?)    (encode-array-like 2 (set->list v))]
+       [(? dict?)   (encode-array-like 3 (dict-keys-and-values v))]
 
-    [_ (error 'encode-value "Cannot encode value ~v" v)]))
+       [_ (error 'encode-value "Cannot encode value ~v" v)])]))
 
 ;;---------------------------------------------------------------------------