diff --git a/iolib.asd b/iolib.asd
index a513e1fa..a9bc9011 100644
--- a/iolib.asd
+++ b/iolib.asd
@@ -357,7 +357,7 @@
   :licence "MIT"
   :version (:read-file-form "version.sexp")
   :defsystem-depends-on (:iolib/base)
-  :depends-on (:fiveam :iolib :iolib/pathnames)
+  :depends-on (:fiveam :iolib :iolib/os :iolib/pathnames)
   :around-compile "iolib/asdf:compile-wrapper"
   :encoding :utf-8
   :pathname "tests/"
@@ -369,7 +369,8 @@
      :pathname #+unix "file-paths-unix")
    (:file "events" :depends-on ("pkgdcl" "defsuites"))
    (:file "streams" :depends-on ("pkgdcl" "defsuites"))
-   (:file "sockets" :depends-on ("pkgdcl" "defsuites"))))
+   (:file "sockets" :depends-on ("pkgdcl" "defsuites"))
+   (:file "os" :depends-on ("pkgdcl" "defsuites"))))
 
 (defsystem :iolib/examples
   :description "Examples for IOLib tutorial at http://pages.cs.wisc.edu/~psilord/blog/data/iolib-tutorial/tutorial.html"
diff --git a/tests/defsuites.lisp b/tests/defsuites.lisp
index 435729d6..824db94e 100644
--- a/tests/defsuites.lisp
+++ b/tests/defsuites.lisp
@@ -17,3 +17,5 @@
 (def-suite :iolib.streams :in :iolib)
 
 (def-suite :iolib.sockets :in :iolib)
+
+(def-suite :iolib.os :in :iolib)
diff --git a/tests/os.lisp b/tests/os.lisp
new file mode 100644
index 00000000..8342fce3
--- /dev/null
+++ b/tests/os.lisp
@@ -0,0 +1,38 @@
+;;;; -*- Mode: Lisp; indent-tabs-mode: nil -*-
+;;;
+;;; --- iolib.os test suite.
+
+(in-package :iolib-tests)
+
+(in-suite :iolib.os)
+
+#+unix
+(test (run-program/pipes-do-not-block :compile-at :definition-time)
+  ;; Try to output a lot of data (more than the pipe buffer size) to stdout and stderr
+  ;; and see how RUN-PROGRAM deals with it.
+  (let* ((data-file "/bin/sh")
+         (data-file-length (with-open-file (stream data-file)
+                             (file-length stream)))
+         (command (concatenate 'string "/bin/cat " data-file)))
+    (flet
+        ((run-program* (&rest args)
+           (format *error-output* "~&;; Calling ~S on ~S~%" 'iolib.os:run-program args)
+           (iolib.os:run-program args :stdin :pipe :stdout :pipe :external-format :iso-8859-1)))
+      (is (< (expt 2 16) data-file-length)
+          "The ~S test is useless if the data file is smaller than the pipe buffer size."
+          'run-program/pipes-do-not-block)
+      (finishes
+        (multiple-value-bind (return-code stdout stderr)
+            (run-program* "/bin/sh" "-c" command)
+          (is (= 0 return-code))
+          (is (= data-file-length (length stdout)))
+          (is (= 0 (length stderr)))))
+      (finishes
+        ;; As of this writing the following call will hang. The reason is that RUN-PROGRAM
+        ;; tries to fully read the stdout pipe without simultaneously reading stderr, but
+        ;; this invocation only writes to stderr and thus eventually overfills the stderr pipe.
+        (multiple-value-bind (return-code stdout stderr)
+            (run-program* "/bin/sh" "-c" (concatenate 'string command " 1>&2"))
+          (is (= 0 return-code))
+          (is (= 0 (length stdout)))
+          (is (= data-file-length (length stderr))))))))