diff --git a/core/vectors/vectors-tests.factor b/core/vectors/vectors-tests.factor
index ea44df4b06..4215185793 100644
--- a/core/vectors/vectors-tests.factor
+++ b/core/vectors/vectors-tests.factor
@@ -1,6 +1,6 @@
 USING: arrays kernel kernel.private math namespaces
 sequences sequences.private strings tools.test vectors
-continuations random growable ;
+continuations random growable classes ;
 IN: temporary
 
 [ ] [ 10 [ [ -1000000 <vector> ] catch drop ] times ] unit-test
@@ -93,3 +93,7 @@ IN: temporary
 [ t ] [
     100 >array dup >vector <reversed> >array >r reverse r> =
 ] unit-test
+
+[ fixnum ] [ 1 >bignum V{ } new length class ] unit-test
+
+[ fixnum ] [ 1 >bignum [ ] V{ } map-as length class ] unit-test
diff --git a/core/vectors/vectors.factor b/core/vectors/vectors.factor
index 2973431650..661ef9ddc8 100644
--- a/core/vectors/vectors.factor
+++ b/core/vectors/vectors.factor
@@ -14,7 +14,7 @@ M: vector like
         dup array? [ dup length array>vector ] [ >vector ] if
     ] unless ;
 
-M: vector new drop [ f <array> ] keep array>vector ;
+M: vector new drop [ f <array> ] keep >fixnum array>vector ;
 
 M: vector equal?
     over vector? [ sequence= ] [ 2drop f ] if ;