diff --git a/include/bitcoin/system/chain/checkpoint.hpp b/include/bitcoin/system/chain/checkpoint.hpp
index 5543442979..1befd7373c 100644
--- a/include/bitcoin/system/chain/checkpoint.hpp
+++ b/include/bitcoin/system/chain/checkpoint.hpp
@@ -21,7 +21,6 @@
 
 #include <iostream>
 #include <memory>
-#include <string>
 #include <vector>
 #include <bitcoin/system/data/data.hpp>
 #include <bitcoin/system/define.hpp>
@@ -39,6 +38,7 @@ class BC_API checkpoint
 
     DEFAULT_COPY_MOVE_DESTRUCT(checkpoint);
 
+    static bool is_at(const list& checkpoints, size_t height) NOEXCEPT;
     static bool is_under(const list& checkpoints, size_t height) NOEXCEPT;
     static bool is_conflict(const list& checkpoints, const hash_digest& hash,
         size_t height) NOEXCEPT;
diff --git a/src/chain/checkpoint.cpp b/src/chain/checkpoint.cpp
index 93f6169b47..e9958dc0a3 100644
--- a/src/chain/checkpoint.cpp
+++ b/src/chain/checkpoint.cpp
@@ -20,7 +20,6 @@
 
 #include <algorithm>
 #include <iostream>
-#include <string>
 #include <utility>
 #include <bitcoin/system/data/data.hpp>
 #include <bitcoin/system/hash/hash.hpp>
@@ -32,9 +31,18 @@ namespace libbitcoin {
 namespace system {
 namespace chain {
 
+bool checkpoint::is_at(const list& checkpoints, size_t height) NOEXCEPT
+{
+    return std::any_of(checkpoints.begin(), checkpoints.end(),
+        [&](const auto& item) NOEXCEPT
+        {
+            return height == item.height();
+        });
+}
+
 bool checkpoint::is_under(const list& checkpoints, size_t height) NOEXCEPT
 {
-    // False if empty, optimial if checkpoints sorted by increasing height.
+    // False if empty, optimal if checkpoints sorted by increasing height.
     return std::any_of(checkpoints.rbegin(), checkpoints.rend(),
         [&](const auto& item) NOEXCEPT
         {
@@ -45,13 +53,14 @@ bool checkpoint::is_under(const list& checkpoints, size_t height) NOEXCEPT
 bool checkpoint::is_conflict(const list& checkpoints, const hash_digest& hash,
     size_t height) NOEXCEPT
 {
+    //  Conflict if height matches and hash does not.
     const auto it = std::find_if(checkpoints.begin(), checkpoints.end(),
         [&](const auto& item) NOEXCEPT
         {
             return height == item.height();
         });
 
-    return it != checkpoints.end() && it->hash() == hash;
+    return it != checkpoints.end() && it->hash() != hash;
 }
 
 // Constructors.
diff --git a/test/chain/checkpoint.cpp b/test/chain/checkpoint.cpp
index 53aacc3e27..9a44779c82 100644
--- a/test/chain/checkpoint.cpp
+++ b/test/chain/checkpoint.cpp
@@ -166,6 +166,79 @@ BOOST_AUTO_TEST_CASE(checkpoint__equality__different__expected)
     BOOST_REQUIRE(!(instance1 == instance2));
 }
 
+BOOST_AUTO_TEST_CASE(checkpoint__is_at__empty__false)
+{
+    const checkpoints points{};
+    BOOST_REQUIRE(!checkpoint::is_at(points, 0));
+    BOOST_REQUIRE(!checkpoint::is_at(points, 42));
+}
+
+BOOST_AUTO_TEST_CASE(checkpoint__is_at__non_empty__expected)
+{
+    const checkpoints points
+    {
+        { "0000000000000000000000000000000000000000000000000000000000000000", 17 },
+        { "0102030405060708090a0102030405060708090a0102030405060708090a0b0c", 42 },
+        { "1111111111111111111111111111111111111111111111111111111111111111", 1000 }
+    };
+
+    BOOST_REQUIRE(!checkpoint::is_at(points, 0));
+    BOOST_REQUIRE(!checkpoint::is_at(points, 1));
+    BOOST_REQUIRE(checkpoint::is_at(points, 17));
+    BOOST_REQUIRE(checkpoint::is_at(points, 42));
+    BOOST_REQUIRE(checkpoint::is_at(points, 1000));
+    BOOST_REQUIRE(!checkpoint::is_at(points, 1001));
+}
+
+BOOST_AUTO_TEST_CASE(checkpoint__is_under__empty__false)
+{
+    const checkpoints points{};
+    BOOST_REQUIRE(!checkpoint::is_under(points, 0));
+    BOOST_REQUIRE(!checkpoint::is_under(points, 42));
+}
+
+BOOST_AUTO_TEST_CASE(checkpoint__is_under__non_empty__expected)
+{
+    const checkpoints points
+    {
+        { "0000000000000000000000000000000000000000000000000000000000000000", 17 },
+        { "0102030405060708090a0102030405060708090a0102030405060708090a0b0c", 42 },
+        { "1111111111111111111111111111111111111111111111111111111111111111", 1000 }
+    };
+
+    BOOST_REQUIRE(checkpoint::is_under(points, 0));
+    BOOST_REQUIRE(checkpoint::is_under(points, 1));
+    BOOST_REQUIRE(checkpoint::is_under(points, 17));
+    BOOST_REQUIRE(checkpoint::is_under(points, 42));
+    BOOST_REQUIRE(checkpoint::is_under(points, 1000));
+    BOOST_REQUIRE(!checkpoint::is_under(points, 1001));
+}
+
+BOOST_AUTO_TEST_CASE(checkpoint__is_conflict__empty__false)
+{
+    const checkpoints points{};
+    const checkpoint point("0102030405060708090a0102030405060708090a0102030405060708090a0b0c", 42);
+    BOOST_REQUIRE(!checkpoint::is_conflict(points, point.hash(), 0));
+    BOOST_REQUIRE(!checkpoint::is_conflict(points, point.hash(), point.height()));
+}
+
+BOOST_AUTO_TEST_CASE(checkpoint__is_conflict__non_empty__expected)
+{
+    const checkpoints points
+    {
+        { "0000000000000000000000000000000000000000000000000000000000000000", 17 },
+        { "0102030405060708090a0102030405060708090a0102030405060708090a0b0c", 42 },
+        { "1111111111111111111111111111111111111111111111111111111111111111", 1000 }
+    };
+    const auto hash = base16_hash("0102030405060708090a0102030405060708090a0102030405060708090a0b0c");
+
+    BOOST_REQUIRE(!checkpoint::is_conflict(points, hash, 0));
+    BOOST_REQUIRE(checkpoint::is_conflict(points, hash, 17));
+    BOOST_REQUIRE(!checkpoint::is_conflict(points, hash, 42));
+    BOOST_REQUIRE(checkpoint::is_conflict(points, hash, 1000));
+    BOOST_REQUIRE(!checkpoint::is_conflict(points, hash, 1001));
+}
+
 // json
 // ----------------------------------------------------------------------------