diff --git a/tests/unit_tests/checkpoints.cpp b/tests/unit_tests/checkpoints.cpp
new file mode 100644
index 000000000..0d7bd4de9
--- /dev/null
+++ b/tests/unit_tests/checkpoints.cpp
@@ -0,0 +1,140 @@
+// Copyright (c) 2012-2013 The Cryptonote developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "gtest/gtest.h"
+
+#include "cryptonote_core/checkpoints.cpp"
+
+using namespace cryptonote;
+
+
+TEST(checkpoints_is_alternative_block_allowed, handles_empty_checkpoins)
+{
+  checkpoints cp;
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(0, 0));
+
+  ASSERT_TRUE(cp.is_alternative_block_allowed(1, 1));
+  ASSERT_TRUE(cp.is_alternative_block_allowed(1, 9));
+  ASSERT_TRUE(cp.is_alternative_block_allowed(9, 1));
+}
+
+TEST(checkpoints_is_alternative_block_allowed, handles_one_checkpoint)
+{
+  checkpoints cp;
+  cp.add_checkpoint(5, "0000000000000000000000000000000000000000000000000000000000000000");
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(0, 0));
+
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 1));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 4));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 5));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 6));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 9));
+
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 1));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 4));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 5));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 6));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 9));
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(5, 1));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(5, 4));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(5, 5));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(5, 6));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(5, 9));
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(6, 1));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(6, 4));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(6, 5));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(6, 6));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(6, 9));
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(9, 1));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(9, 4));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(9, 5));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(9, 6));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(9, 9));
+}
+
+TEST(checkpoints_is_alternative_block_allowed, handles_two_and_more_checkpoints)
+{
+  checkpoints cp;
+  cp.add_checkpoint(5, "0000000000000000000000000000000000000000000000000000000000000000");
+  cp.add_checkpoint(9, "0000000000000000000000000000000000000000000000000000000000000000");
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(0, 0));
+
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 1));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 4));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 5));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 6));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 8));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 9));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 10));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(1, 11));
+
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 1));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 4));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 5));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 6));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 8));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 9));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 10));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(4, 11));
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(5, 1));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(5, 4));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(5, 5));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(5, 6));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(5, 8));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(5, 9));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(5, 10));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(5, 11));
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(6, 1));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(6, 4));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(6, 5));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(6, 6));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(6, 8));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(6, 9));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(6, 10));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(6, 11));
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(8, 1));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(8, 4));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(8, 5));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(8, 6));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(8, 8));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(8, 9));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(8, 10));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(8, 11));
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(9, 1));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(9, 4));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(9, 5));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(9, 6));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(9, 8));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(9, 9));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(9, 10));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(9, 11));
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(10, 1));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(10, 4));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(10, 5));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(10, 6));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(10, 8));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(10, 9));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(10, 10));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(10, 11));
+
+  ASSERT_FALSE(cp.is_alternative_block_allowed(11, 1));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(11, 4));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(11, 5));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(11, 6));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(11, 8));
+  ASSERT_FALSE(cp.is_alternative_block_allowed(11, 9));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(11, 10));
+  ASSERT_TRUE (cp.is_alternative_block_allowed(11, 11));
+}