diff --git a/xenomorph/xenomorph/array.rkt b/xenomorph/xenomorph/array.rkt
index 2d534016..9304fe43 100644
--- a/xenomorph/xenomorph/array.rkt
+++ b/xenomorph/xenomorph/array.rkt
@@ -14,7 +14,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
 |#
 
 (define x:array%
-  (class x:enobase%
+  (class xenobase%
     (super-new)
     (init-field [(@type type)] [(@len len)] [(@length-type length-type)])
     
@@ -32,7 +32,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
                                       '_currentOffset 0
                                       '_length @len)
                              parent))
-      (define len (resolve-length @len port #:parent parent))
+      (define len (resolve-length @len port parent))
       (cond
         [(or (not len) (eq? @length-type 'bytes))
          (define end-pos (cond
@@ -84,7 +84,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
              (define items-size (for/sum ([item val])
                                   (send @type x:size item new-parent)))
              (+ items-size len-size)]
-        [else (define count (resolve-length @len #f #:parent parent))
+        [else (define count (resolve-length @len #f parent))
               (define size (send @type x:size #f parent))
               (* size count)]))))
 
diff --git a/xenomorph/xenomorph/bitfield.rkt b/xenomorph/xenomorph/bitfield.rkt
index b2ea5ee0..d863e1d5 100644
--- a/xenomorph/xenomorph/bitfield.rkt
+++ b/xenomorph/xenomorph/bitfield.rkt
@@ -8,7 +8,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Bitfield.coffee
 |#
 
 (define x:bitfield%
-  (class x:enobase%
+  (class xenobase%
     (super-new)
     (init-field [(@type type)][(@flags flags)])
     (unless (andmap (λ (f) (or (symbol? f) (not f))) @flags)
diff --git a/xenomorph/xenomorph/buffer.rkt b/xenomorph/xenomorph/buffer.rkt
index 4c339f8d..f6c29ea0 100644
--- a/xenomorph/xenomorph/buffer.rkt
+++ b/xenomorph/xenomorph/buffer.rkt
@@ -8,14 +8,14 @@ https://github.com/mbutterick/restructure/blob/master/src/Buffer.coffee
 |#
 
 (define x:buffer%
-  (class x:enobase%
+  (class xenobase%
     (super-new)
     (init-field [(@len len)])
     (unless (length-resolvable? @len)
       (raise-argument-error '+xbuffer "resolvable length" @len))
 
     (define/augment (x:decode port parent)
-      (define len (resolve-length @len port #:parent parent))
+      (define len (resolve-length @len port parent))
       (read-bytes len))
 
     (define/augment (x:encode buf port [parent #f])
@@ -30,7 +30,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Buffer.coffee
                   (raise-argument-error 'xbuffer-size "bytes" val)))
       (if (bytes? val)
           (bytes-length val)
-          (resolve-length @len val #:parent parent)))))
+          (resolve-length @len val parent)))))
 
 (define (x:buffer [len-arg #f]
                   #:length [len-kwarg #f]
diff --git a/xenomorph/xenomorph/enum.rkt b/xenomorph/xenomorph/enum.rkt
index 6a3f945b..909e8dfb 100644
--- a/xenomorph/xenomorph/enum.rkt
+++ b/xenomorph/xenomorph/enum.rkt
@@ -8,7 +8,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Enum.coffee
 |#
 
 (define x:enum%
-  (class x:enobase%
+  (class xenobase%
     (super-new)
     (init-field [(@type type)] [(@values values)])
      
diff --git a/xenomorph/xenomorph/helper.rkt b/xenomorph/xenomorph/helper.rkt
index b9f0b145..8e54f951 100644
--- a/xenomorph/xenomorph/helper.rkt
+++ b/xenomorph/xenomorph/helper.rkt
@@ -38,7 +38,7 @@
                  (define (size xo [val #f] #:parent [parent #f])
                    (send xo x:size val parent)))])))
 
-(define (xenomorphic-type? x) (is-a? x x:enobase%))
+(define (xenomorphic-type? x) (is-a? x xenobase%))
 
 (define-syntax-rule (generate-subclass CLASS PRE-ENCODE-PROC POST-DECODE-PROC)
   (cond
@@ -57,7 +57,7 @@
        (define/override (post-decode x) (POST-DECODE-PROC (super post-decode x))))]
     [else CLASS]))
 
-(define x:enobase%
+(define xenobase%
   (class* object% (x:enomorphic<%>)
     (super-new)
     
diff --git a/xenomorph/xenomorph/lazy-array.rkt b/xenomorph/xenomorph/lazy-array.rkt
index 97a18b0b..3e843384 100644
--- a/xenomorph/xenomorph/lazy-array.rkt
+++ b/xenomorph/xenomorph/lazy-array.rkt
@@ -15,7 +15,7 @@ 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 len (resolve-length @len port parent))
       (define new-parent (if (x:int? @len)
                              (mhasheq 'parent parent
                                       '_startOffset starting-pos
diff --git a/xenomorph/xenomorph/number.rkt b/xenomorph/xenomorph/number.rkt
index 5efb9b0b..b099bab6 100644
--- a/xenomorph/xenomorph/number.rkt
+++ b/xenomorph/xenomorph/number.rkt
@@ -24,7 +24,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Number.coffee
 (define system-endian (if (system-big-endian?) 'be 'le))
 
 (define x:number%
-  (class x:enobase%
+  (class xenobase%
     (super-new)
     (init-field [(@size size)] [(@endian endian)])
     
diff --git a/xenomorph/xenomorph/optional.rkt b/xenomorph/xenomorph/optional.rkt
index 8db1a58f..78ef7bbf 100644
--- a/xenomorph/xenomorph/optional.rkt
+++ b/xenomorph/xenomorph/optional.rkt
@@ -8,7 +8,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Optional.coffee
 |#
 
 (define x:optional%
-  (class x:enobase%
+  (class xenobase%
     (super-new)
     (init-field [(@type type)] [(@condition condition)])
 
diff --git a/xenomorph/xenomorph/pointer.rkt b/xenomorph/xenomorph/pointer.rkt
index f9854eaf..b603bdd4 100644
--- a/xenomorph/xenomorph/pointer.rkt
+++ b/xenomorph/xenomorph/pointer.rkt
@@ -24,7 +24,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Pointer.coffee
     [else (raise-argument-error 'Pointer:size "VoidPointer" val)]))
 
 (define x:pointer%
-  (class x:enobase%
+  (class xenobase%
     (super-new)
     (init-field [(@offset-type offset-type)]
                 [(@type type)]
@@ -112,7 +112,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Pointer.coffee
        [null-value null-value]))
 
 ;; A pointer whose type is determined at decode time
-(define x:void-pointer% (class x:enobase%
+(define x:void-pointer% (class xenobase%
                          (super-new)
                          (init-field type value)))
 (define (x:void-pointer . args) (apply make-object x:void-pointer% args))
diff --git a/xenomorph/xenomorph/reserved.rkt b/xenomorph/xenomorph/reserved.rkt
index 0668ab71..772e898d 100644
--- a/xenomorph/xenomorph/reserved.rkt
+++ b/xenomorph/xenomorph/reserved.rkt
@@ -8,12 +8,12 @@ https://github.com/mbutterick/restructure/blob/master/src/Reserved.coffee
 |#
 
 (define x:reserved%
-  (class x:enobase%
+  (class xenobase%
     (super-new)
     (init-field [(@type type)] [(@count count)])
 
     (unless (xenomorphic-type? @type)
-      (raise-argument-error '+xoptional"xenomorphic type" @type))
+      (raise-argument-error '+xoptional "xenomorphic type" @type))
 
     (define/augment (x:decode port parent)
       (pos port (+ (pos port) (x:size #f parent)))
@@ -23,7 +23,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Reserved.coffee
       (make-bytes (x:size val parent) 0))
     
     (define/augment (x:size [val #f] [parent #f])
-      (* (send @type x:size) (resolve-length @count #f #:parent parent)))))
+      (* (send @type x:size) (resolve-length @count #f parent)))))
 
 (define (x:reserved [type-arg #f] [count-arg #f]
                     #:type [type-kwarg #f]
diff --git a/xenomorph/xenomorph/string.rkt b/xenomorph/xenomorph/string.rkt
index a12c4b73..6bcd96bf 100644
--- a/xenomorph/xenomorph/string.rkt
+++ b/xenomorph/xenomorph/string.rkt
@@ -29,7 +29,7 @@ https://github.com/mbutterick/restructure/blob/master/src/String.coffee
   (not (eof-object? (peek-byte port))))
 
 (define x:string%
-  (class x:enobase%
+  (class xenobase%
     (super-new)
     (init-field [(@len len)] [(@encoding encoding)])
 
@@ -39,7 +39,7 @@ https://github.com/mbutterick/restructure/blob/master/src/String.coffee
       (raise-argument-error 'xstring (format "procedure or member of ~v" supported-encodings) @encoding))
 
     (define/augment (x:decode port parent)
-      (define len (or (resolve-length @len port #:parent parent) (count-nonzero-chars port)))
+      (define len (or (resolve-length @len port parent) (count-nonzero-chars port)))
       (define encoding (if (procedure? @encoding)
                            (or (@encoding parent) 'ascii)
                            @encoding))
@@ -77,7 +77,7 @@ https://github.com/mbutterick/restructure/blob/master/src/String.coffee
                                    [(x:int? @len) (send @len x:size)]
                                    [else 0]))
              (+ string-size strlen-size)]
-        [else (resolve-length @len #f #:parent parent)]))))
+        [else (resolve-length @len #f parent)]))))
 
 (define supported-encodings '(ascii utf8))
 (define (x:string [len-arg #f] [enc-arg #f]
diff --git a/xenomorph/xenomorph/struct.rkt b/xenomorph/xenomorph/struct.rkt
index 70045d24..1b982fab 100644
--- a/xenomorph/xenomorph/struct.rkt
+++ b/xenomorph/xenomorph/struct.rkt
@@ -46,7 +46,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Struct.coffee
   h)
 
 (define x:struct%
-  (class x:enobase%
+  (class xenobase%
     (super-new)
     (init-field [(@fields fields)])
     
diff --git a/xenomorph/xenomorph/util.rkt b/xenomorph/xenomorph/util.rkt
index 044b9c80..e4e2ef72 100644
--- a/xenomorph/xenomorph/util.rkt
+++ b/xenomorph/xenomorph/util.rkt
@@ -5,7 +5,7 @@
 (define (length-resolvable? x)
   (or (not x) (symbol? x) (xenomorphic? x) (procedure? x) (exact-nonnegative-integer? x)))
 
-(define (resolve-length x port #:parent [parent #f])
+(define (resolve-length x port [parent #f])
   (cond
     [(not x) #f]
     [(exact-nonnegative-integer? x) x]