diff --git a/basis/math/vectors/simd/simd-tests.factor b/basis/math/vectors/simd/simd-tests.factor
index 535a671359..f7c051fdce 100644
--- a/basis/math/vectors/simd/simd-tests.factor
+++ b/basis/math/vectors/simd/simd-tests.factor
@@ -81,9 +81,13 @@ CONSTANT: simd-classes
 : check-optimizer ( seq inputs quot eq-quot -- )
     '[
         @
-        [ "print-mr" get [ nip test-mr mr. ] [ 2drop ] if ]
-        [ [ call ] dip call ]
-        [ [ call ] dip compile-call ] 2tri @ not
+        {
+            [ "print-mr" get [ nip test-mr mr. ] [ 2drop ] if ]
+            [ "print-checks" get [ [ . ] bi@ ] [ 2drop ] if ]
+            [ [ call ] dip call ]
+            [ [ call ] dip compile-call ]
+        } 2cleave
+        @ not
     ] filter ; inline
 
 "== Checking -new constructors" print
diff --git a/basis/math/vectors/vectors.factor b/basis/math/vectors/vectors.factor
index 1bd202f2ad..e3e4f51e28 100644
--- a/basis/math/vectors/vectors.factor
+++ b/basis/math/vectors/vectors.factor
@@ -61,8 +61,8 @@ PRIVATE>
 : vbitor ( u v -- w ) over '[ _ [ bitor ] fp-bitwise-op ] 2map ;
 : vbitxor ( u v -- w ) over '[ _ [ bitxor ] fp-bitwise-op ] 2map ;
 
-: vlshift ( u n -- w ) HEX: ff bitand '[ _ shift ] map ;
-: vrshift ( u n -- w ) HEX: ff bitand neg '[ _ shift ] map ;
+: vlshift ( u n -- w ) HEX: ffffffff bitand '[ _ shift ] map ;
+: vrshift ( u n -- w ) HEX: ffffffff bitand neg '[ _ shift ] map ;
 
 : vfloor    ( u -- v ) [ floor ] map ;
 : vceiling  ( u -- v ) [ ceiling ] map ;