diff --git a/collects/scribblings/reference/numbers.scrbl b/collects/scribblings/reference/numbers.scrbl
index ab4b086697..1fb34737c9 100644
--- a/collects/scribblings/reference/numbers.scrbl
+++ b/collects/scribblings/reference/numbers.scrbl
@@ -596,7 +596,7 @@ but faster and in constant time when @scheme[n] is positive.
                             [start exact-nonnegative-integer?] 
                             [end (and/c exact-nonnegative-integer?
                                         (start . <= . end))])
-         boolean?]{
+         exact-integer?]{
 
 Returns
 
diff --git a/collects/scribblings/reference/unsafe.scrbl b/collects/scribblings/reference/unsafe.scrbl
index d0c581e7ef..06de73b20a 100644
--- a/collects/scribblings/reference/unsafe.scrbl
+++ b/collects/scribblings/reference/unsafe.scrbl
@@ -70,8 +70,9 @@ the result is always a @tech{fixnum}. The @scheme[unsafe-fxlshift] and
 @scheme[unsafe-fxlshift] is a positive (i.e., left) shift, and
 @scheme[unsafe-fxrshift] is a negative (i.e., right) shift, where the
 number of bits to shift must be less than the number of bits used to
-represent a @tech{fixnum}, and the result is effectively
-@scheme[bitwise-and]ed with the most negative @tech{fixnum}.}
+represent a @tech{fixnum}. In the case of @scheme[unsafe-fxlshift],
+bits in the result beyond the the number of bits used to represent a
+@tech{fixnum} are effectively replaced with a copy of the high bit.}
 
 
 @deftogether[(