diff --git a/racket/src/ChezScheme/mats/date.ms b/racket/src/ChezScheme/mats/date.ms
index 72c2f464f2..c8780222dd 100644
--- a/racket/src/ChezScheme/mats/date.ms
+++ b/racket/src/ChezScheme/mats/date.ms
@@ -506,6 +506,10 @@
     (and (date? $date-d5) (not (time? $date-d5))))
   (date? (make-date 0 0 0 0 1 1 1970 -24))
   (date? (make-date 999999999 59 59 23 31 12 2007 24))
+  (begin
+    (define $date-d8 (make-date 999999999 59 59 23 31 12 2007 24))
+    #t)
+  (not (fixnum? (date-nanosecond $date-d8)))
   (eqv? (date-nanosecond $date-d1) 1)
   (eqv? (date-second $date-d1) 2)
   (eqv? (date-minute $date-d1) 3)
diff --git a/racket/src/ChezScheme/s/primdata.ss b/racket/src/ChezScheme/s/primdata.ss
index 28435fcf6d..628c89f161 100644
--- a/racket/src/ChezScheme/s/primdata.ss
+++ b/racket/src/ChezScheme/s/primdata.ss
@@ -860,7 +860,7 @@
   (date-hour [sig [(date) -> (fixnum)]] [flags pure mifoldable discard true])
   (date-minute [sig [(date) -> (fixnum)]] [flags pure mifoldable discard true])
   (date-month [sig [(date) -> (fixnum)]] [flags pure mifoldable discard true])
-  (date-nanosecond [sig [(date) -> (fixnum)]] [flags pure mifoldable discard true])
+  (date-nanosecond [sig [(date) -> (uint)]] [flags pure mifoldable discard true])
   (date-second [sig [(date) -> (fixnum)]] [flags pure mifoldable discard true])
   (date-week-day [sig [(date) -> (fixnum)]] [flags pure mifoldable discard true])
   (date-year-day [sig [(date) -> (fixnum)]] [flags pure mifoldable discard true])
@@ -869,8 +869,8 @@
   (date-zone-offset [sig [(date) -> (fixnum)]] [flags pure mifoldable discard true])
   (date-zone-name [sig [(date) -> (ptr)]] [flags pure mifoldable discard])
   (date->time-utc [sig [(date) -> (time-utc)]] [flags alloc])
-  (make-date [sig [(sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum) -> (date)]
-                  [(sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-fixnum) -> (date)]]
+  (make-date [sig [(sub-uint sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum) -> (date)]
+                  [(sub-uint sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-ufixnum sub-fixnum) -> (date)]]
              [flags alloc])
   (make-time [sig [(sub-symbol sub-uint exact-integer) -> (time)]] [flags alloc])
   (set-time-nanosecond! [sig [(time sub-uint) -> (void)]] [flags true])