diff --git a/tests/base.scm b/tests/base.scm
index 8732b436..2424d020 100644
--- a/tests/base.scm
+++ b/tests/base.scm
@@ -17,5 +17,19 @@
   (test '() (make-list -2))
 )
 
+(test-group
+  "I/O"
+  (define p (open-input-string "one\ntwo\n"))
+  (test #\o (read-char p))
+  (test "ne" (read-line p))
+  (test "two" (read-line p))
+  (test (eof-object) (read-line p))
+  (define p (open-input-string "one\ntwo\n"))
+  (test "one" (read-line p))
+  (test #\t (read-char p))
+  (test #\w (read-char p))
+  (test "o" (read-line p))
+)
+
 (test-exit)