diff --git a/test/Jamfile b/test/Jamfile
index b5fb7fb..5569435 100644
--- a/test/Jamfile
+++ b/test/Jamfile
@@ -29,3 +29,4 @@ run test_num_digits.cpp ;
 run limits_link_1.cpp limits_link_2.cpp limits_link_3.cpp ;
 run test_128bit_native.cpp ;
 run test_128bit_emulation.cpp ;
+run leading_zero_count.cpp ;
diff --git a/test/leading_zero_count.cpp b/test/leading_zero_count.cpp
new file mode 100644
index 0000000..71454cb
--- /dev/null
+++ b/test/leading_zero_count.cpp
@@ -0,0 +1,45 @@
+// Copyright 2023 Matt Borland
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/charconv/detail/leading_zeros.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <limits>
+#include <cstdint>
+
+template <typename T>
+void test()
+{
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(1), 63);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(2), 62);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(3), 62);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(4), 61);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(8), 60);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(16), 59);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(32), 58);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(64), 57);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(128), 56);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(200), 56);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(256), 55);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(500), 55);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(512), 54);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(1000), 54);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(1024), 53);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(std::numeric_limits<T>::max() - 1), 0);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(std::numeric_limits<T>::max()), 0);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(std::numeric_limits<T>::max() / 2 + 1), 0);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(std::numeric_limits<T>::max() / 2), 1);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(std::numeric_limits<T>::max() / 4 + 1), 1);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(std::numeric_limits<T>::max() / 4), 2);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(std::numeric_limits<T>::max() / 8), 3);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(std::numeric_limits<T>::max() / 16), 4);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(std::numeric_limits<T>::max() / 32), 5);
+    BOOST_TEST_EQ(boost::charconv::detail::leading_zeros(std::numeric_limits<T>::max() / 64), 6);
+}
+
+int main(void)
+{
+    test<std::uint64_t>();
+
+    return boost::report_errors();
+}