diff --git a/LOG b/LOG
index 14147a9476..34b29b2d69 100644
--- a/LOG
+++ b/LOG
@@ -1752,3 +1752,7 @@
     configure
 - fixed declaration of condition wait (timeout -> maybe-timeout)
     primdata.ms
+- added "invalid code page ~s" to set of messages considered valid
+  argument-type-check error messages, for Windows multibyte->string
+  and string->multibyte.
+    primvars.ms
diff --git a/mats/primvars.ms b/mats/primvars.ms
index 560c70f8f5..9fefa0d552 100644
--- a/mats/primvars.ms
+++ b/mats/primvars.ms
@@ -623,7 +623,8 @@
                                                                              "~s is not between 2 and 36"
                                                                              "invalid palette ~s"
                                                                              "bit argument ~s is not 0 or 1"
-                                                                             "unrecognized type ~s")))
+                                                                             "unrecognized type ~s"
+                                                                             "invalid code page ~s")))
                                                                     (equal? (condition-irritants c) (list bad)))
                                                                (and (or (member (condition-message c)
                                                                           '("~s is not a valid index for ~s"