diff --git a/lib/chibi/diff-test.sld b/lib/chibi/diff-test.sld
index 534ff81d..c45b5d92 100644
--- a/lib/chibi/diff-test.sld
+++ b/lib/chibi/diff-test.sld
@@ -7,23 +7,24 @@
    (else
     ;; inline (chibi test) to avoid circular dependencies in snow
     ;; installations
-    (define-syntax test
-      (syntax-rules ()
-        ((test expect expr)
-         (test 'expr expect expr))
-        ((test name expect expr)
-         (guard (exn (else (display "!\nERROR: ") (write name) (newline)
-                           (write exn) (newline)))
-           (let* ((res expr)
-                  (pass? (equal? expect expr)))
-             (display (if pass? "." "x"))
-             (cond
-              ((not pass?)
-               (display "\nFAIL: ") (write name) (newline))))))))
-    (define (test-begin name)
-      (display name))
-    (define (test-end)
-      (newline))))
+    (begin
+      (define-syntax test
+        (syntax-rules ()
+          ((test expect expr)
+           (test 'expr expect expr))
+          ((test name expect expr)
+           (guard (exn (else (display "!\nERROR: ") (write name) (newline)
+                             (write exn) (newline)))
+             (let* ((res expr)
+                    (pass? (equal? expect expr)))
+               (display (if pass? "." "x"))
+               (cond
+                ((not pass?)
+                 (display "\nFAIL: ") (write name) (newline))))))))
+      (define (test-begin name)
+        (display name))
+      (define (test-end)
+        (newline)))))
   (begin
     (define (run-tests)
       (test-begin "diff")
diff --git a/lib/chibi/optional-test.sld b/lib/chibi/optional-test.sld
index 845576e7..7f76fce6 100644
--- a/lib/chibi/optional-test.sld
+++ b/lib/chibi/optional-test.sld
@@ -6,27 +6,31 @@
    (else
     ;; inline (chibi test) to avoid circular dependencies in snow
     ;; installations
-    (define-syntax test
-      (syntax-rules ()
-        ((test expect expr)
-         (test 'expr expect expr))
-        ((test name expect expr)
-         (guard (exn (else (display "!\nERROR: ") (write name) (newline)
-                           (write exn) (newline)))
-           (let* ((res expr)
-                  (pass? (equal? expect expr)))
-             (display (if pass? "." "x"))
-             (cond
-              ((not pass?)
-               (display "\nFAIL: ") (write name) (newline))))))))
-    (define-syntax test-error
-      (syntax-rules ()
-        ((test-error expr)
-         (test-assert (guard (exn (else #t)) expr #f)))))
-    (define (test-begin name)
-      (display name))
-    (define (test-end)
-      (newline))))
+    (begin
+      (define-syntax test
+       (syntax-rules ()
+         ((test expect expr)
+          (test 'expr expect expr))
+         ((test name expect expr)
+          (guard (exn (else (display "!\nERROR: ") (write name) (newline)
+                            (write exn) (newline)))
+            (let* ((res expr)
+                   (pass? (equal? expect expr)))
+              (display (if pass? "." "x"))
+              (cond
+               ((not pass?)
+                (display "\nFAIL: ") (write name) (newline))))))))
+      (define-syntax test-assert
+        (syntax-rules ()
+          ((test-assert expr) (test #t expr))))
+      (define-syntax test-error
+        (syntax-rules ()
+          ((test-error expr)
+           (test-assert (guard (exn (else #t)) expr #f)))))
+      (define (test-begin name)
+        (display name))
+      (define (test-end)
+        (newline)))))
   (export run-tests)
   (begin
     (define (run-tests)