diff --git a/thirdparty/grisu2/grisu2.h b/thirdparty/grisu2/grisu2.h
index 19886cce47f..dbc09755fad 100644
--- a/thirdparty/grisu2/grisu2.h
+++ b/thirdparty/grisu2/grisu2.h
@@ -1,15 +1,12 @@
-#ifndef SIMDJSON_SRC_TO_CHARS_CPP
-#define SIMDJSON_SRC_TO_CHARS_CPP
-
-#include <base.h>
+#pragma once
 
 #include <cstring>
 #include <cstdint>
 #include <array>
 #include <cmath>
 
-namespace simdjson {
-namespace internal {
+namespace grisu2 {
 /*!
 implements the Grisu2 algorithm for binary to decimal floating-point
 conversion.
@@ -26,7 +23,6 @@ PLDI 2010 [2] Burger, Dybvig, "Printing Floating-Point Numbers Quickly and
 Accurately", Proceedings of the ACM SIGPLAN 1996 Conference on Programming
 Language Design and Implementation, PLDI 1996
 */
-namespace dtoa_impl {
 
 template <typename Target, typename Source>
 Target reinterpret_bits(const Source source) {
@@ -718,7 +714,7 @@ v = buf * 10^decimal_exponent
 len is the length of the buffer (number of decimal digits)
 The buffer must be large enough, i.e. >= max_digits10.
 */
-inline void grisu2(char *buf, int &len, int &decimal_exponent, diyfp m_minus,
+inline void grisu2_core(char *buf, int &len, int &decimal_exponent, diyfp m_minus,
                    diyfp v, diyfp m_plus) {
 
   //  --------(-----------------------+-----------------------)--------    (A)
@@ -775,7 +771,7 @@ len is the length of the buffer (number of decimal digits)
 The buffer must be large enough, i.e. >= max_digits10.
 */
 template <typename FloatType>
-void grisu2(char *buf, int &len, int &decimal_exponent, FloatType value) {
+void grisu2_wrap(char *buf, int &len, int &decimal_exponent, FloatType value) {
   static_assert(diyfp::kPrecision >= std::numeric_limits<FloatType>::digits + 3,
                 "internal error: not enough precision");
 
@@ -804,7 +800,7 @@ void grisu2(char *buf, int &len, int &decimal_exponent, FloatType value) {
   const boundaries w = compute_boundaries(value);
 #endif
 
-  grisu2(buf, len, decimal_exponent, w.minus, w.w, w.plus);
+  grisu2_core(buf, len, decimal_exponent, w.minus, w.w, w.plus);
 }
 
 /*!
@@ -864,10 +860,7 @@ inline char *format_buffer(char *buf, int len, int decimal_exponent,
     // len <= max_exp + 2
 
     std::memset(buf + k, '0', static_cast<size_t>(n) - static_cast<size_t>(k));
-    // Make it look like a floating-point number (#362, #378)
-    buf[n + 0] = '.';
-    buf[n + 1] = '0';
-    return buf + (static_cast<size_t>(n)) + 2;
+    return buf + (static_cast<size_t>(n));
   }
 
   if (0 < n && n <= max_exp) {
@@ -909,8 +902,6 @@ inline char *format_buffer(char *buf, int len, int decimal_exponent,
   return append_exponent(buf, n - 1);
 }
 
-} // namespace dtoa_impl
-
 /*!
 The format of the resulting decimal representation is similar to printf's %g
 format. Returns an iterator pointing past-the-end of the decimal representation.
@@ -918,19 +909,15 @@ format. Returns an iterator pointing past-the-end of the decimal representation.
 @note The buffer must be large enough.
 @note The result is NOT null-terminated.
 */
-char *to_chars(char *first, const char *last, double value) {
-  static_cast<void>(last); // maybe unused - fix warning
+template <typename FloatType>
+char *to_chars(char *first, FloatType value) {
   bool negative = std::signbit(value);
   if (negative) {
     value = -value;
     *first++ = '-';
   }
-
   if (value == 0) // +-0
   {
-    *first++ = '0';
-    // Make it look like a floating-point number (#362, #378)
-    *first++ = '.';
     *first++ = '0';
     return first;
   }
@@ -940,15 +927,13 @@ char *to_chars(char *first, const char *last, double value) {
   // len is the length of the buffer, i.e. the number of decimal digits.
   int len = 0;
   int decimal_exponent = 0;
-  dtoa_impl::grisu2(first, len, decimal_exponent, value);
+  grisu2_wrap(first, len, decimal_exponent, value);
   // Format the buffer like printf("%.*g", prec, value)
   constexpr int kMinExp = -4;
   constexpr int kMaxExp = std::numeric_limits<double>::digits10;
 
-  return dtoa_impl::format_buffer(first, len, decimal_exponent, kMinExp,
-                                  kMaxExp);
+  return format_buffer(first, len, decimal_exponent, kMinExp, kMaxExp);
 }
-} // namespace internal
-} // namespace simdjson
+} // namespace grisu2
 
-#endif // SIMDJSON_SRC_TO_CHARS_CPP