diff --git a/include/boost/json/detail/charconv/detail/fast_float/float_common.hpp b/include/boost/json/detail/charconv/detail/fast_float/float_common.hpp
index ef3114005..a280095e8 100644
--- a/include/boost/json/detail/charconv/detail/fast_float/float_common.hpp
+++ b/include/boost/json/detail/charconv/detail/fast_float/float_common.hpp
@@ -273,7 +273,7 @@ struct binary_format_lookup_tables<double, U> {
 
   // Largest integer value v so that (5**index * v) <= 1<<53.
   // 0x10000000000000 == 1 << 53
-  static constexpr std::uint64_t max_mantissa[] = {
+  static constexpr uint64_t max_mantissa[] = {
     UINT64_C(0x10000000000000),
     UINT64_C(0x10000000000000) / UINT64_C(5),
     UINT64_C(0x10000000000000) / (UINT64_C(5) * UINT64_C(5)),
diff --git a/include/boost/json/impl/value_stack.ipp b/include/boost/json/impl/value_stack.ipp
index af1b107b2..4c3dbac23 100644
--- a/include/boost/json/impl/value_stack.ipp
+++ b/include/boost/json/impl/value_stack.ipp
@@ -434,7 +434,7 @@ push_string(
 void
 value_stack::
 push_int64(
-    int64_t i)
+    std::int64_t i)
 {
     st_.push(i, sp_);
 }
@@ -442,7 +442,7 @@ push_int64(
 void
 value_stack::
 push_uint64(
-    uint64_t u)
+    std::uint64_t u)
 {
     st_.push(u, sp_);
 }