diff --git a/xenomorph/xenomorph/array.rkt b/xenomorph/xenomorph/array.rkt
index 13efad95..2d534016 100644
--- a/xenomorph/xenomorph/array.rkt
+++ b/xenomorph/xenomorph/array.rkt
@@ -26,7 +26,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
       (raise-argument-error '+xarray "'bytes or 'count" @length-type))
 
     (define/augride (x:decode port parent)
-      (define new-parent (if (xint? @len)
+      (define new-parent (if (x:int? @len)
                              (mhasheq 'parent parent
                                       '_startOffset (pos port)
                                       '_currentOffset 0
@@ -62,7 +62,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
           (for ([item array])
             (send @type x:encode item port parent))))
       (cond
-        [(xint? @len)
+        [(x:int? @len)
          (define new-parent (mhash 'pointers null
                                    'startOffset (pos port)
                                    'parent parent))
@@ -78,7 +78,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
                   (raise-argument-error 'xarray-size "sequence" val)))
       (cond
         [val (define-values (new-parent len-size)
-               (if (xint? @len)
+               (if (x:int? @len)
                    (values (mhasheq 'parent parent) (send @len x:size))
                    (values parent 0)))
              (define items-size (for/sum ([item val])
diff --git a/xenomorph/xenomorph/buffer.rkt b/xenomorph/xenomorph/buffer.rkt
index 67cffa0a..4c339f8d 100644
--- a/xenomorph/xenomorph/buffer.rkt
+++ b/xenomorph/xenomorph/buffer.rkt
@@ -21,7 +21,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Buffer.coffee
     (define/augment (x:encode buf port [parent #f])
       (unless (bytes? buf)
         (raise-argument-error 'xbuffer-encode "bytes" buf))
-      (when (xint? @len)
+      (when (x:int? @len)
         (send @len x:encode (bytes-length buf) port))
       (write-bytes buf port))
     
diff --git a/xenomorph/xenomorph/lazy-array.rkt b/xenomorph/xenomorph/lazy-array.rkt
index 69c1c2f0..97a18b0b 100644
--- a/xenomorph/xenomorph/lazy-array.rkt
+++ b/xenomorph/xenomorph/lazy-array.rkt
@@ -16,7 +16,7 @@ https://github.com/mbutterick/restructure/blob/master/src/LazyArray.coffee
     (define/override (x:decode port parent)
       (define starting-pos (pos port)) ; ! placement matters. `resolve-length` will change `pos`
       (define len (resolve-length @len port #:parent parent))
-      (define new-parent (if (xint? @len)
+      (define new-parent (if (x:int? @len)
                              (mhasheq 'parent parent
                                       '_startOffset starting-pos
                                       '_currentOffset 0
diff --git a/xenomorph/xenomorph/number.rkt b/xenomorph/xenomorph/number.rkt
index 0d81ab80..5efb9b0b 100644
--- a/xenomorph/xenomorph/number.rkt
+++ b/xenomorph/xenomorph/number.rkt
@@ -37,7 +37,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Number.coffee
     
     (define/augment (x:size . _) @size)))
 
-(define (xint? x) (is-a? x x:int%))
+(define (x:int? x) (is-a? x x:int%))
 
 (define x:int%
   (class x:number%
diff --git a/xenomorph/xenomorph/string.rkt b/xenomorph/xenomorph/string.rkt
index 239739ff..a12c4b73 100644
--- a/xenomorph/xenomorph/string.rkt
+++ b/xenomorph/xenomorph/string.rkt
@@ -57,7 +57,7 @@ https://github.com/mbutterick/restructure/blob/master/src/String.coffee
       (define encoded-length (bytes-length encoded-str))
       (when (and (exact-nonnegative-integer? @len) (> encoded-length @len))
         (raise-argument-error 'xstring-encode (format "string no longer than ~a" @len) val)) 
-      (when (xint? @len)
+      (when (x:int? @len)
         (send @len x:encode encoded-length port parent))
       (define string-terminator (if (not @len) (bytes 0) (bytes))) ; null terminated when no len
       (bytes-append encoded-str string-terminator)) 
@@ -74,7 +74,7 @@ https://github.com/mbutterick/restructure/blob/master/src/String.coffee
              (define string-size (bytes-length (encode-string val encoding)))
              (define strlen-size (cond
                                    [(not @len) 1]
-                                   [(xint? @len) (send @len x:size)]
+                                   [(x:int? @len) (send @len x:size)]
                                    [else 0]))
              (+ string-size strlen-size)]
         [else (resolve-length @len #f #:parent parent)]))))
diff --git a/xenomorph/xenomorph/util.rkt b/xenomorph/xenomorph/util.rkt
index e4df07ec..044b9c80 100644
--- a/xenomorph/xenomorph/util.rkt
+++ b/xenomorph/xenomorph/util.rkt
@@ -11,5 +11,5 @@
     [(exact-nonnegative-integer? x) x]
     [(procedure? x) (x parent)]
     [(and parent (symbol? x)) (dict-ref parent x)]
-    [(and port (xint? x)) (decode x port)]
+    [(and port (x:int? x)) (decode x port)]
     [else (raise-argument-error 'resolve-length "fixed-size argument" x)]))
\ No newline at end of file