diff --git a/ipatests/test_ipaserver/test_install/test_installutils.py b/ipatests/test_ipaserver/test_install/test_installutils.py
new file mode 100644
index 000000000..cc8fd3cf3
--- /dev/null
+++ b/ipatests/test_ipaserver/test_install/test_installutils.py
@@ -0,0 +1,57 @@
+#
+# Copyright (C) 2017  FreeIPA Contributors.  See COPYING for license
+#
+
+import os
+import tempfile
+
+from ipaserver.install import installutils
+
+EXAMPLE_CONFIG = [
+    'foo=1\n',
+    'foobar=2\n',
+]
+
+
+class test_set_directive_lines(object):
+    def test_remove_directive(self):
+        lines = installutils.set_directive_lines(
+            False, '=', 'foo', None, EXAMPLE_CONFIG)
+        assert list(lines) == ['foobar=2\n']
+
+    def test_add_directive(self):
+        lines = installutils.set_directive_lines(
+            False, '=', 'baz', '4', EXAMPLE_CONFIG)
+        assert list(lines) == ['foo=1\n', 'foobar=2\n', 'baz=4\n']
+
+    def test_set_directive_does_not_clobber_suffix_key(self):
+        lines = installutils.set_directive_lines(
+            False, '=', 'foo', '3', EXAMPLE_CONFIG)
+        assert list(lines) == ['foo=3\n', 'foobar=2\n']
+
+
+class test_set_directive(object):
+    def test_set_directive(self):
+        """Check that set_directive writes the new data and preserves mode."""
+        fd, filename = tempfile.mkstemp()
+        try:
+            os.close(fd)
+            stat_pre = os.stat(filename)
+
+            with open(filename, 'w') as f:
+                for line in EXAMPLE_CONFIG:
+                    f.write(line)
+
+            installutils.set_directive(filename, 'foo', '3', False, '=')
+
+            stat_post = os.stat(filename)
+            with open(filename, 'r') as f:
+                lines = list(f)
+
+            assert lines == ['foo=3\n', 'foobar=2\n']
+            assert stat_pre.st_mode == stat_post.st_mode
+            assert stat_pre.st_uid == stat_post.st_uid
+            assert stat_pre.st_gid == stat_post.st_gid
+
+        finally:
+            os.remove(filename)