Index: uspace/lib/c/Makefile
===================================================================
--- uspace/lib/c/Makefile	(revision d57c7c22ec10cecc3ee30ee28e44f7702e425a37)
+++ uspace/lib/c/Makefile	(revision cdf6066f21385be78f0b5bbfbdde1d1c20cbed4a)
@@ -196,4 +196,5 @@
 	test/stdio/scanf.c \
 	test/odict.c \
+	test/perm.c \
 	test/qsort.c \
 	test/sprintf.c \
Index: uspace/lib/c/test/main.c
===================================================================
--- uspace/lib/c/test/main.c	(revision d57c7c22ec10cecc3ee30ee28e44f7702e425a37)
+++ uspace/lib/c/test/main.c	(revision cdf6066f21385be78f0b5bbfbdde1d1c20cbed4a)
@@ -37,4 +37,5 @@
 PCUT_IMPORT(mem);
 PCUT_IMPORT(odict);
+PCUT_IMPORT(perm);
 PCUT_IMPORT(qsort);
 PCUT_IMPORT(scanf);
Index: uspace/lib/c/test/perm.c
===================================================================
--- uspace/lib/c/test/perm.c	(revision cdf6066f21385be78f0b5bbfbdde1d1c20cbed4a)
+++ uspace/lib/c/test/perm.c	(revision cdf6066f21385be78f0b5bbfbdde1d1c20cbed4a)
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2018 Jiri Svoboda
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * - Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ * - The name of the author may not be used to endorse or promote products
+ *   derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <task.h>
+#include <pcut/pcut.h>
+#include <perm.h>
+
+PCUT_INIT;
+
+PCUT_TEST_SUITE(perm);
+
+PCUT_TEST(revoke)
+{
+	errno_t rc = perm_revoke(task_get_id(), 0xf); // XXX Need PERM_xxx
+	PCUT_ASSERT_ERRNO_VAL(EOK, rc);
+}
+
+PCUT_EXPORT(perm);