diff --git a/src/libstrongswan/crypto/proposal/proposal.c b/src/libstrongswan/crypto/proposal/proposal.c
index 7e5486577..1fb6ee6d9 100644
--- a/src/libstrongswan/crypto/proposal/proposal.c
+++ b/src/libstrongswan/crypto/proposal/proposal.c
@@ -111,23 +111,49 @@ static int type_find(const void *a, const void *b)
 /**
  * Check if the given transform type is already in the set
  */
-static bool contains_type(private_proposal_t *this, transform_type_t type)
+static bool contains_type(array_t *types, transform_type_t type)
 {
-	return array_bsearch(this->types, &type, type_find, NULL) != -1;
+	return array_bsearch(types, &type, type_find, NULL) != -1;
 }
 
 /**
  * Add the given transform type to the set
  */
-static void add_type(private_proposal_t *this, transform_type_t type)
+static void add_type(array_t *types, transform_type_t type)
 {
-	if (!contains_type(this, type))
+	if (!contains_type(types, type))
 	{
-		array_insert(this->types, ARRAY_TAIL, &type);
-		array_sort(this->types, type_sort, NULL);
+		array_insert(types, ARRAY_TAIL, &type);
+		array_sort(types, type_sort, NULL);
 	}
 }
 
+/**
+ * Merge two sets of transform types into a new array
+ */
+static array_t *merge_types(private_proposal_t *this, private_proposal_t *other)
+{
+	array_t *types;
+	transform_type_t type;
+	int i, count;
+
+	count = max(array_count(this->types), array_count(other->types));
+	types = array_create(sizeof(transform_type_t), count);
+
+	for (i = 0; i < count; i++)
+	{
+		if (array_get(this->types, i, &type))
+		{
+			add_type(types, type);
+		}
+		if (array_get(other->types, i, &type))
+		{
+			add_type(types, type);
+		}
+	}
+	return types;
+}
+
 /**
  * Remove the given transform type from the set
  */
@@ -165,7 +191,7 @@ METHOD(proposal_t, add_algorithm, void,
 	};
 
 	array_insert(this->transforms, ARRAY_TAIL, &entry);
-	add_type(this, type);
+	add_type(this->types, type);
 }
 
 CALLBACK(alg_filter, bool,
@@ -397,6 +423,9 @@ METHOD(proposal_t, select_proposal, proposal_t*,
 	bool private)
 {
 	proposal_t *selected;
+	transform_type_t type;
+	array_t *types;
+	int i;
 
 	DBG2(DBG_CFG, "selecting proposal:");
 
@@ -415,18 +444,20 @@ METHOD(proposal_t, select_proposal, proposal_t*,
 	{
 		selected = proposal_create(this->protocol, this->number);
 		selected->set_spi(selected, this->spi);
-
 	}
 
-	if (!select_algo(this, other, selected, ENCRYPTION_ALGORITHM, private) ||
-		!select_algo(this, other, selected, PSEUDO_RANDOM_FUNCTION, private) ||
-		!select_algo(this, other, selected, INTEGRITY_ALGORITHM, private) ||
-		!select_algo(this, other, selected, DIFFIE_HELLMAN_GROUP, private) ||
-		!select_algo(this, other, selected, EXTENDED_SEQUENCE_NUMBERS, private))
+	types = merge_types(this, (private_proposal_t*)other);
+	for (i = 0; i < array_count(types); i++)
 	{
-		selected->destroy(selected);
-		return NULL;
+		array_get(types, i, &type);
+		if (!select_algo(this, other, selected, type, private))
+		{
+			selected->destroy(selected);
+			array_destroy(types);
+			return NULL;
+		}
 	}
+	array_destroy(types);
 
 	DBG2(DBG_CFG, "  proposal matches");
 	return selected;
diff --git a/src/libstrongswan/tests/suites/test_proposal.c b/src/libstrongswan/tests/suites/test_proposal.c
index 947c32159..9f8cc7e1f 100644
--- a/src/libstrongswan/tests/suites/test_proposal.c
+++ b/src/libstrongswan/tests/suites/test_proposal.c
@@ -204,14 +204,66 @@ START_TEST(test_unknown_transform_types_print)
 	proposal->destroy(proposal);
 
 	proposal = proposal_create_from_string(PROTO_IKE,
-										   "aes128-sha256-modp3072-ecp256");
+										   "aes128-sha256-ecp256");
 	proposal->add_algorithm(proposal, 242, 42, 128);
 	proposal->add_algorithm(proposal, 243, 1, 0);
-	assert_proposal_eq(proposal, "IKE:AES_CBC_128/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/MODP_3072/ECP_256/UNKNOWN_242_42_128/UNKNOWN_243_1");
+	assert_proposal_eq(proposal, "IKE:AES_CBC_128/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/ECP_256/UNKNOWN_242_42_128/UNKNOWN_243_1");
 	proposal->destroy(proposal);
 }
 END_TEST
 
+START_TEST(test_unknown_transform_types_select_fail)
+{
+	proposal_t *self, *other, *selected;
+
+	self = proposal_create_from_string(PROTO_IKE, "aes128-sha256-ecp256");
+	other = proposal_create_from_string(PROTO_IKE, "aes128-sha256-ecp256");
+	other->add_algorithm(other, 242, 42, 0);
+
+	selected = self->select(self, other, TRUE, FALSE);
+	ck_assert(!selected);
+	other->destroy(other);
+	self->destroy(self);
+}
+END_TEST
+
+START_TEST(test_unknown_transform_types_select_fail_subtype)
+{
+	proposal_t *self, *other, *selected;
+
+	self = proposal_create_from_string(PROTO_IKE, "aes128-sha256-ecp256");
+	self->add_algorithm(self, 242, 8, 0);
+	other = proposal_create_from_string(PROTO_IKE, "aes128-sha256-ecp256");
+	other->add_algorithm(other, 242, 42, 0);
+
+	selected = self->select(self, other, TRUE, FALSE);
+	ck_assert(!selected);
+	other->destroy(other);
+	self->destroy(self);
+}
+END_TEST
+
+START_TEST(test_unknown_transform_types_select_success)
+{
+	proposal_t *self, *other, *selected;
+
+	self = proposal_create_from_string(PROTO_IKE, "aes128-sha256-ecp256");
+	self->add_algorithm(self, 242, 42, 128);
+	other = proposal_create_from_string(PROTO_IKE, "aes128-sha256-ecp256");
+	other->add_algorithm(other, 242, 42, 128);
+	other->add_algorithm(other, 242, 1, 0);
+
+	selected = self->select(self, other, TRUE, FALSE);
+	ck_assert(selected);
+	assert_proposal_eq(selected, "IKE:AES_CBC_128/HMAC_SHA2_256_128/PRF_HMAC_SHA2_256/ECP_256/UNKNOWN_242_42_128");
+	selected->destroy(selected);
+	other->destroy(other);
+	self->destroy(self);
+}
+END_TEST
+
+
+
 Suite *proposal_suite_create()
 {
 	Suite *s;
@@ -236,6 +288,9 @@ Suite *proposal_suite_create()
 
 	tc = tcase_create("unknown transform types");
 	tcase_add_test(tc, test_unknown_transform_types_print);
+	tcase_add_test(tc, test_unknown_transform_types_select_fail);
+	tcase_add_test(tc, test_unknown_transform_types_select_fail_subtype);
+	tcase_add_test(tc, test_unknown_transform_types_select_success);
 	suite_add_tcase(s, tc);
 
 	return s;