diff --git a/src/libstrongswan/ipsec/ipsec_types.c b/src/libstrongswan/ipsec/ipsec_types.c
index 68c3935b9..c992eb5ad 100644
--- a/src/libstrongswan/ipsec/ipsec_types.c
+++ b/src/libstrongswan/ipsec/ipsec_types.c
@@ -104,7 +104,10 @@ bool mark_from_string(const char *value, mark_t *mark)
 	{
 		mark->mask = 0xffffffff;
 	}
-	/* apply the mask to ensure the value is in range */
-	mark->value &= mark->mask;
+	if (!MARK_IS_UNIQUE(mark->value))
+	{
+		/* apply the mask to ensure the value is in range */
+		mark->value &= mark->mask;
+	}
 	return TRUE;
 }
diff --git a/src/libstrongswan/tests/suites/test_utils.c b/src/libstrongswan/tests/suites/test_utils.c
index 353010aaf..b423d7d2d 100644
--- a/src/libstrongswan/tests/suites/test_utils.c
+++ b/src/libstrongswan/tests/suites/test_utils.c
@@ -877,8 +877,23 @@ static struct {
 	{"/0xff",		TRUE,  { 0, 0xff }},
 	{"/x",			FALSE, { 0 }},
 	{"x/x",			FALSE, { 0 }},
-	{"0xffffffff/0x0000ffff",	TRUE, { 0x0000ffff, 0x0000ffff }},
-	{"0xffffffff/0xffffffff",	TRUE, { 0xffffffff, 0xffffffff }},
+	{"0xfffffff0/0x0000ffff",	TRUE,  { 0x0000fff0, 0x0000ffff }},
+	{"%unique",					TRUE,  { MARK_UNIQUE, 0xffffffff }},
+	{"%unique/",				TRUE,  { MARK_UNIQUE, 0 }},
+	{"%unique/0x0000ffff",		TRUE,  { MARK_UNIQUE, 0x0000ffff }},
+	{"%unique/0xffffffff",		TRUE,  { MARK_UNIQUE, 0xffffffff }},
+	{"%unique0xffffffffff",		FALSE, { 0, 0 }},
+	{"0xffffffff/0x0000ffff",	TRUE,  { MARK_UNIQUE, 0x0000ffff }},
+	{"0xffffffff/0xffffffff",	TRUE,  { MARK_UNIQUE, 0xffffffff }},
+	{"%unique-dir",				TRUE,  { MARK_UNIQUE_DIR, 0xffffffff }},
+	{"%unique-dir/",			TRUE,  { MARK_UNIQUE_DIR, 0 }},
+	{"%unique-dir/0x0000ffff",	TRUE,  { MARK_UNIQUE_DIR, 0x0000ffff }},
+	{"%unique-dir/0xffffffff",	TRUE,  { MARK_UNIQUE_DIR, 0xffffffff }},
+	{"%unique-dir0xffffffff",	FALSE, { 0, 0 }},
+	{"0xfffffffe/0x0000ffff",	TRUE,  { MARK_UNIQUE_DIR, 0x0000ffff }},
+	{"0xfffffffe/0xffffffff",	TRUE,  { MARK_UNIQUE_DIR, 0xffffffff }},
+	{"%unique-/0xffffffff",		FALSE, { 0, 0 }},
+	{"%unique-foo/0xffffffff",	FALSE, { 0, 0 }},
 };
 
 START_TEST(test_mark_from_string)