diff --git a/.gitignore b/.gitignore
index edd567f..90b1430 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
+/*.c
+/*.o*
 /test*.tar
diff --git a/test-chibi.scm b/test-r7rs.scm
similarity index 82%
rename from test-chibi.scm
rename to test-r7rs.scm
index e6de675..b212296 100755
--- a/test-chibi.scm
+++ b/test-r7rs.scm
@@ -1,4 +1,4 @@
-#! /usr/bin/env chibi-scheme
+#!
 
 (import (scheme base)
         (scheme file)
@@ -17,9 +17,6 @@
              whole
              (loop (bytevector-append whole part))))))))
 
-(tar-write-file "hello/world.text"
-                (slurp-binary-file "trivial-tar-writer.scm"))
-
 (define (main arguments)
   (for-each (lambda (file) (tar-write-file file (slurp-binary-file file)))
             (cdr arguments)))
diff --git a/test.sh b/test.sh
index a78be35..6edf69b 100755
--- a/test.sh
+++ b/test.sh
@@ -1,9 +1,14 @@
 #!/bin/sh
-set -eux
-./test-chibi.scm trivial-tar-writer.scm >test-our.tar
-bsdtar -cf test-bsd.tar trivial-tar-writer.scm
-gtar -cf test-gnu.tar trivial-tar-writer.scm
-hexdump -C test-our.tar
+set -eu
+cd "$(dirname "$0")"
+echo "Entering directory '$PWD'"
+set -x
+payload=trivial-tar-writer.scm
+chibi-scheme -A . test-r7rs.scm $payload >test-chibi.tar
+gsi-script . test-r7rs.scm $payload >test-gambit.tar
+bsdtar -cf test-bsd.tar $payload
+gtar -cf test-gnu.tar $payload
+hexdump -C test-chibi.tar
 echo
 echo
 echo