diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 864b8d88a..390201085 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,8 @@
+2002-01-10  Corinna Vinschen  <corinna@vinschen.de>
+
+	* syscalls.cc (pathconf): Guard _PC_PATH_MAX branch against invalid
+	file parameter.
+
 2002-01-09  Christopher Faylor  <cgf@redhat.com>
             Robert Collins  <rbtcollins@hotmail.com>
 
diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index 7686eb155..8812a4ab6 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -1424,6 +1424,8 @@ pathconf (const char *file, int v)
   switch (v)
     {
     case _PC_PATH_MAX:
+      if (check_null_empty_str_errno (file))
+          return -1;
       return PATH_MAX - strlen (file);
     case _PC_NAME_MAX:
       return PATH_MAX;