diff --git a/tests/unix/mod_os.py b/tests/unix/mod_os.py
new file mode 100644
index 0000000000..17554d9375
--- /dev/null
+++ b/tests/unix/mod_os.py
@@ -0,0 +1,21 @@
+# This module is not entirely compatible with CPython
+import os
+
+
+os.putenv("TEST_VARIABLE", "TEST_VALUE")
+
+print(os.getenv("TEST_VARIABLE"))
+print(os.getenv("TEST_VARIABLE", "TEST_DEFAULT_VALUE"))
+
+os.unsetenv("TEST_VARIABLE")
+
+print(os.getenv("TEST_VARIABLE"))
+print(os.getenv("TEST_VARIABLE", "TEST_DEFAULT_VALUE"))
+
+print(os.system("true"))
+
+rand = os.urandom(4)
+print(type(rand) is bytes, len(rand))
+
+os.errno(2)
+print(os.errno())
diff --git a/tests/unix/mod_os.py.exp b/tests/unix/mod_os.py.exp
new file mode 100644
index 0000000000..465163085b
--- /dev/null
+++ b/tests/unix/mod_os.py.exp
@@ -0,0 +1,7 @@
+TEST_VALUE
+TEST_VALUE
+None
+TEST_DEFAULT_VALUE
+0
+True 4
+2