diff --git a/basis/specialized-arrays/direct/functor/functor.factor b/basis/specialized-arrays/direct/functor/functor.factor
index b49dfa35e4..89d1b5423d 100755
--- a/basis/specialized-arrays/direct/functor/functor.factor
+++ b/basis/specialized-arrays/direct/functor/functor.factor
@@ -8,6 +8,7 @@ IN: specialized-arrays.direct.functor
 FUNCTOR: define-direct-array ( T -- )
 
 A'      IS ${T}-array
+S       IS ${T}-sequence
 >A'     IS >${T}-array
 <A'>    IS <${A'}>
 A'{     IS ${A'}{
@@ -24,6 +25,8 @@ TUPLE: A
 { underlying c-ptr read-only }
 { length fixnum read-only } ;
 
+INSTANCE: A S
+
 : <A> ( alien len -- direct-array ) A boa ; inline
 M: A length length>> ;
 M: A nth-unsafe underlying>> NTH call ;
diff --git a/basis/specialized-arrays/functor/functor.factor b/basis/specialized-arrays/functor/functor.factor
index 06b9aef17d..a8d8d677ec 100644
--- a/basis/specialized-arrays/functor/functor.factor
+++ b/basis/specialized-arrays/functor/functor.factor
@@ -16,6 +16,7 @@ M: bad-byte-array-length summary
 FUNCTOR: define-array ( T -- )
 
 A            DEFINES-CLASS ${T}-array
+S            DEFINES-CLASS ${T}-sequence
 <A>          DEFINES <${A}>
 (A)          DEFINES (${A})
 >A           DEFINES >${A}
@@ -27,10 +28,14 @@ SET-NTH      [ T dup c-setter array-accessor ]
 
 WHERE
 
+MIXIN: S
+
 TUPLE: A
 { length array-capacity read-only }
 { underlying byte-array read-only } ;
 
+INSTANCE: A S
+
 : <A> ( n -- specialized-array ) dup T <c-array> A boa ; inline
 
 : (A) ( n -- specialized-array ) dup T (c-array) A boa ; inline
diff --git a/basis/specialized-vectors/functor/functor.factor b/basis/specialized-vectors/functor/functor.factor
index 08c44cd197..48c480b4d1 100644
--- a/basis/specialized-vectors/functor/functor.factor
+++ b/basis/specialized-vectors/functor/functor.factor
@@ -10,6 +10,7 @@ FUNCTOR: define-vector ( T -- )
 V   DEFINES-CLASS ${T}-vector
 
 A   IS      ${T}-array
+S   IS      ${T}-sequence
 <A> IS      <${A}>
 
 >V  DEFERS >${V}
@@ -19,6 +20,8 @@ WHERE
 
 V A <A> vectors.functor:define-vector
 
+INSTANCE: V S
+
 M: V contract 2drop ;
 
 M: V byte-length underlying>> byte-length ;