diff --git a/test-suite/tests/filesys.test b/test-suite/tests/filesys.test
index 45e77c823..f99677de0 100644
--- a/test-suite/tests/filesys.test
+++ b/test-suite/tests/filesys.test
@@ -394,14 +394,21 @@
     (stat:perms (stat (test-file))))
 
   (pass-if-exception "not a port" exception:wrong-type-arg
+    (unless (defined? 'chmodat)
+      (throw 'unsupported))
     (chmodat "bogus" (test-file) #o300))
 
   (pass-if-exception "not a file port" exception:wrong-type-arg
+    (unless (defined? 'chmodat)
+      (throw 'unsupported))
     (chmodat (open-input-string "") (test-file) #o300))
 
   (pass-if-exception "closed port" exception:wrong-type-arg
+    (unless (defined? 'chmodat)
+      (throw 'unsupported))
     (chmodat (call-with-port (open "." O_RDONLY) identity) (test-file) #o300))
 
+  (chmod (test-file) #o600)
   (delete-file (test-file)))
 
 (with-test-prefix "chdir"
@@ -474,10 +481,10 @@
           (readlink '(stuff)))))
 
   (pass-if-equal "port representing a regular file" EINVAL
+    (unless (provided? 'readlink-port)
+      (throw 'unsupported))
     (call-with-input-file (test-file)
       (lambda (port)
-        (unless (provided? 'readlink-port)
-          (throw 'unsupported))
         (catch 'system-error
           (lambda ()
             (readlink port)