diff --git a/core/bootstrap/primitives.factor b/core/bootstrap/primitives.factor
index 9858ccb5ec..3e93a868ca 100755
--- a/core/bootstrap/primitives.factor
+++ b/core/bootstrap/primitives.factor
@@ -441,6 +441,7 @@ builtins get num-tags get tail f union-class define-class
     { "fixnum-bitxor" "math.private" }
     { "fixnum-bitnot" "math.private" }
     { "fixnum-shift" "math.private" }
+    { "fixnum-shift-fast" "math.private" }
     { "fixnum<" "math.private" }
     { "fixnum<=" "math.private" }
     { "fixnum>" "math.private" }
diff --git a/vm/math.c b/vm/math.c
index a8bc76c2b1..8c4e7d537a 100644
--- a/vm/math.c
+++ b/vm/math.c
@@ -166,6 +166,12 @@ DEFINE_PRIMITIVE(fixnum_shift)
 		fixnum_to_bignum(x),y)));
 }
 
+DEFINE_PRIMITIVE(fixnum_shift_fast)
+{
+	POP_FIXNUMS(x,y)
+	dpush(tag_fixnum(y < 0 ? (x >> -y) : (x << y)));
+}
+
 DEFINE_PRIMITIVE(fixnum_less)
 {
 	POP_FIXNUMS(x,y)
diff --git a/vm/math.h b/vm/math.h
index 7e427b4833..d82a373571 100644
--- a/vm/math.h
+++ b/vm/math.h
@@ -22,6 +22,7 @@ DECLARE_PRIMITIVE(fixnum_and);
 DECLARE_PRIMITIVE(fixnum_or);
 DECLARE_PRIMITIVE(fixnum_xor);
 DECLARE_PRIMITIVE(fixnum_shift);
+DECLARE_PRIMITIVE(fixnum_shift_fast);
 DECLARE_PRIMITIVE(fixnum_less);
 DECLARE_PRIMITIVE(fixnum_lesseq);
 DECLARE_PRIMITIVE(fixnum_greater);
diff --git a/vm/primitives.c b/vm/primitives.c
index 9bc1323eae..dd96ee1495 100755
--- a/vm/primitives.c
+++ b/vm/primitives.c
@@ -33,6 +33,7 @@ void *primitives[] = {
 	primitive_fixnum_xor,
 	primitive_fixnum_not,
 	primitive_fixnum_shift,
+	primitive_fixnum_shift_fast,
 	primitive_fixnum_less,
 	primitive_fixnum_lesseq,
 	primitive_fixnum_greater,