diff --git a/include/boost/charconv/detail/from_chars_float_impl.hpp b/include/boost/charconv/detail/from_chars_float_impl.hpp
index bd0b1730..a1a63c88 100644
--- a/include/boost/charconv/detail/from_chars_float_impl.hpp
+++ b/include/boost/charconv/detail/from_chars_float_impl.hpp
@@ -26,7 +26,7 @@ namespace boost { namespace charconv { namespace detail {
 # pragma GCC diagnostic push
 # pragma GCC diagnostic ignored "-Wmissing-field-initializers"
 # pragma GCC diagnostic ignored "-Wfloat-conversion"
-#elif defined(__clang__) && __clang_major__ >= 7
+#elif defined(__clang__) && __clang_major__ > 7
 # pragma clang diagnostic push
 # pragma clang diagnostic ignored "-Wimplicit-float-conversion"
 #elif defined(__clang__) && __clang_major__ < 7
diff --git a/test/from_chars.cpp b/test/from_chars.cpp
index 07f1a7ce..09ed3669 100644
--- a/test/from_chars.cpp
+++ b/test/from_chars.cpp
@@ -134,7 +134,7 @@ void overflow_test()
     }
     else
     {
-        BOOST_TEST(r1.ec == std::errc()) && BOOST_TEST_EQ(v1, static_cast<T>(1234));
+        BOOST_TEST(r1.ec == std::errc()) && BOOST_TEST_EQ(v1, 1234);
     }
 
     const char* buffer2 = "123456789123456789123456789";
diff --git a/test/test_128bit_native.cpp b/test/test_128bit_native.cpp
index 4e5c71cd..61e1dd64 100644
--- a/test/test_128bit_native.cpp
+++ b/test/test_128bit_native.cpp
@@ -10,19 +10,19 @@
 void test128()
 {
     auto r1 = boost::charconv::detail::umul128(1, 1);
-    BOOST_TEST_EQ(r1.high, 0);
-    BOOST_TEST_EQ(r1.low, 1);
+    BOOST_TEST_EQ(r1.high, UINT64_C(0));
+    BOOST_TEST_EQ(r1.low, UINT64_C(1));
 
     auto r2 = boost::charconv::detail::umul128(10, std::numeric_limits<std::uint64_t>::max());
-    BOOST_TEST_EQ(r2.high, 9);
+    BOOST_TEST_EQ(r2.high, UINT64_C(9));
     BOOST_TEST_EQ(r2.low, UINT64_C(18446744073709551606));
 
     auto r3 = boost::charconv::detail::umul128(std::numeric_limits<std::uint64_t>::max(), std::numeric_limits<std::uint64_t>::max());
     BOOST_TEST_EQ(r3.high, UINT64_C(18446744073709551614));
-    BOOST_TEST_EQ(r3.low, 1); 
+    BOOST_TEST_EQ(r3.low, UINT64_C(1));
 }
 
-int main(void)
+int main()
 {
     test128();
     return boost::report_errors();
diff --git a/test/test_boost_json_values.cpp b/test/test_boost_json_values.cpp
index f7a3e9b3..b66c70b1 100644
--- a/test/test_boost_json_values.cpp
+++ b/test/test_boost_json_values.cpp
@@ -160,6 +160,7 @@ void issue_599_test()
 #elif defined(__clang__)
 # pragma clang diagnostic push
 # pragma clang diagnostic ignored "-Wfloat-conversion"
+# pragma clang diagnostic ignored "-Wconversion"
 # if __clang_major__ >= 7
 #   pragma clang diagnostic ignored "-Wimplicit-float-conversion"
 # endif