diff --git a/changelog/current.md b/changelog/current.md
index f6d16fb..e2d8d5a 100644
--- a/changelog/current.md
+++ b/changelog/current.md
@@ -1,3 +1,4 @@
 
+- Fix [rapidyaml#445](https://github.com/biojppm/biojppm/pull/445): Amalgamate: fix include of `<charconv>`.
 - Add `bool from_chars(csubstr s, fmt::overflow_checked_<T> *wrapper)`. There was already is a function receiving `&wrapper`, but `*wrapper` was missing for use with generic code.
 - Update fast_float to v6.1.1 ([PR#136](https://github.com/biojppm/c4core/pull/136))
diff --git a/tools/amalgamate.py b/tools/amalgamate.py
index 55487b9..e84a96f 100644
--- a/tools/amalgamate.py
+++ b/tools/amalgamate.py
@@ -30,15 +30,15 @@ def amalgamate_c4core(filename: str,
 #define C4CORE_EXPORTS
 #endif
 """
-    required_gcc4_8_include = """// these includes are needed to work around conditional
-// includes in the gcc4.8 shim
+    required_gcc4_8_include = """// (amalgamate) these includes are needed to work around
+// conditional includes in the gcc4.8 shim
 #include <cstdint>
 #include <type_traits>
 #include <cstring>
 """
-    required_charconv_include = """// this include is needed to work around conditional
-// includes in charconv.hpp
-#if __cplusplus >= 201703L
+    required_charconv_include = """// (amalgamate) this include is needed to work around
+// conditional includes in charconv.hpp
+#if (defined(_MSVC_LANG) && (_MSVC_LANG >= 201703L)) || (__cplusplus >= 201703L)
 #include <charconv>
 #endif
 """