diff --git a/core/alien/alien-docs.factor b/core/alien/alien-docs.factor
index 8ae89ed5b1..8fee0e8c3e 100755
--- a/core/alien/alien-docs.factor
+++ b/core/alien/alien-docs.factor
@@ -34,10 +34,6 @@ HELP: <alien>
 { $description "Creates an alien object, wrapping a raw memory address." }
 { $notes "Alien objects are invalidated between image saves and loads." } ;
 
-HELP: byte-length
-{ $values { "seq" "A byte array or float array" } { "n" "a non-negative integer" } }
-{ $contract "Outputs the size of the byte array or float array data in bytes as presented to the C library interface." } ;
-
 HELP: c-ptr
 { $class-description "Class of objects consisting of aliens, byte arrays and " { $link f } ". These objects can convert to pointer C types, which are all aliases of " { $snippet "void*" } "." } ;
 
diff --git a/core/alien/alien.factor b/core/alien/alien.factor
index 4b899a15e4..1c8163e2fa 100755
--- a/core/alien/alien.factor
+++ b/core/alien/alien.factor
@@ -28,8 +28,6 @@ PREDICATE: alien pinned-alien
 UNION: pinned-c-ptr
     pinned-alien POSTPONE: f ;
 
-GENERIC: byte-length ( seq -- n ) flushable
-
 M: f expired? drop t ;
 
 : <alien> ( address -- alien )
diff --git a/core/alien/c-types/c-types-docs.factor b/core/alien/c-types/c-types-docs.factor
index f6418295f7..f4aa297a3a 100755
--- a/core/alien/c-types/c-types-docs.factor
+++ b/core/alien/c-types/c-types-docs.factor
@@ -34,6 +34,10 @@ HELP: stack-size
 { $description "Outputs the number of bytes to reserve on the C stack by a value of this C type. In most cases this is equal to " { $link heap-size } ", except on some platforms where C structs are passed by invisible reference, in which case a C struct type only uses as much space as a pointer on the C stack." }
 { $errors "Throws a " { $link no-c-type } " error if the type does not exist." } ;
 
+HELP: byte-length
+{ $values { "seq" "A byte array or float array" } { "n" "a non-negative integer" } }
+{ $contract "Outputs the size of the byte array or float array data in bytes as presented to the C library interface." } ;
+
 HELP: c-getter
 { $values { "name" string } { "quot" "a quotation with stack effect " { $snippet "( c-ptr n -- obj )" } } }
 { $description "Outputs a quotation which reads values of this C type from a C structure." }
diff --git a/core/alien/c-types/c-types.factor b/core/alien/c-types/c-types.factor
index 1ecfa37ee6..47f9fd0326 100755
--- a/core/alien/c-types/c-types.factor
+++ b/core/alien/c-types/c-types.factor
@@ -1,6 +1,6 @@
 ! Copyright (C) 2004, 2007 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: byte-arrays arrays generator.registers assocs
+USING: byte-arrays float-arrays arrays generator.registers assocs
 kernel kernel.private libc math namespaces parser sequences
 strings words assocs splitting math.parser cpu.architecture
 alien quotations system compiler.units ;
@@ -107,6 +107,12 @@ M: string stack-size c-type stack-size ;
 
 M: c-type stack-size c-type-size ;
 
+GENERIC: byte-length ( seq -- n ) flushable
+
+M: float-array byte-length length "float" heap-size * ;
+
+M: byte-array byte-length length ;
+
 : c-getter ( name -- quot )
     c-type c-type-getter [
         [ "Cannot read struct fields with type" throw ]
diff --git a/core/byte-arrays/byte-arrays.factor b/core/byte-arrays/byte-arrays.factor
index 295c6c4384..401b151ad0 100755
--- a/core/byte-arrays/byte-arrays.factor
+++ b/core/byte-arrays/byte-arrays.factor
@@ -15,8 +15,6 @@ M: byte-array new drop <byte-array> ;
 M: byte-array equal?
     over byte-array? [ sequence= ] [ 2drop f ] if ;
 
-M: byte-array byte-length
-    length ;
 M: byte-array resize
     resize-byte-array ;
 
diff --git a/core/float-arrays/float-arrays.factor b/core/float-arrays/float-arrays.factor
index 948e41ef7a..445edd550a 100755
--- a/core/float-arrays/float-arrays.factor
+++ b/core/float-arrays/float-arrays.factor
@@ -1,6 +1,6 @@
 ! Copyright (C) 2007, 2008 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: kernel kernel.private alien alien.c-types sequences
+USING: kernel kernel.private alien sequences
 sequences.private math math.private ;
 IN: float-arrays
 
@@ -12,7 +12,6 @@ PRIVATE>
 
 M: float-array clone (clone) ;
 M: float-array length array-capacity ;
-M: float-array byte-length array-capacity "float" heap-size * ;
 
 M: float-array nth-unsafe
     float-array@ alien-double ;