diff --git a/include/yaml-cpp/emitter.h b/include/yaml-cpp/emitter.h
index 3756be1..41675fa 100644
--- a/include/yaml-cpp/emitter.h
+++ b/include/yaml-cpp/emitter.h
@@ -21,7 +21,7 @@
 #include "yaml-cpp/emittermanip.h"
 #include "yaml-cpp/null.h"
 #include "yaml-cpp/ostream_wrapper.h"
-#include "yaml-cpp/fp_to_string.h"
+#include "yaml-cpp/fptostring.h"
 
 namespace YAML {
 class Binary;
diff --git a/include/yaml-cpp/fptostring.h b/include/yaml-cpp/fptostring.h
new file mode 100644
index 0000000..ace79bf
--- /dev/null
+++ b/include/yaml-cpp/fptostring.h
@@ -0,0 +1,22 @@
+// SPDX-FileCopyrightText: 2024 Simon Gene Gottlieb
+// SPDX-License-Identifier: MIT
+
+#ifndef YAML_H_FP_TO_STRING
+#define YAML_H_FP_TO_STRING
+
+#include "contrib/dragonbox.h"
+
+#include <array>
+#include <cassert>
+#include <cmath>
+#include <sstream>
+#include <tuple>
+
+namespace YAML {
+// "precision = 0" refers to shortest known unique representation of the value
+std::string FpToString(float v, size_t precision = 0);
+std::string FpToString(double v, size_t precision = 0);
+std::string FpToString(long double v, size_t precision = 0);
+}
+
+#endif
diff --git a/include/yaml-cpp/node/convert.h b/include/yaml-cpp/node/convert.h
index 3761f79..9ccbf53 100644
--- a/include/yaml-cpp/node/convert.h
+++ b/include/yaml-cpp/node/convert.h
@@ -28,7 +28,7 @@
 #include "yaml-cpp/node/node.h"
 #include "yaml-cpp/node/type.h"
 #include "yaml-cpp/null.h"
-#include "yaml-cpp/fp_to_string.h"
+#include "yaml-cpp/fptostring.h"
 
 
 namespace YAML {
diff --git a/include/yaml-cpp/fp_to_string.h b/src/fptostring.cpp
similarity index 93%
rename from include/yaml-cpp/fp_to_string.h
rename to src/fptostring.cpp
index 380c01f..d12bbc0 100644
--- a/include/yaml-cpp/fp_to_string.h
+++ b/src/fptostring.cpp
@@ -1,14 +1,12 @@
 // SPDX-FileCopyrightText: 2024 Simon Gene Gottlieb
 // SPDX-License-Identifier: MIT
 
-#ifndef YAML_H_FP_TO_STRING
-#define YAML_H_FP_TO_STRING
-
 #include "contrib/dragonbox.h"
 
 #include <array>
 #include <cassert>
 #include <cmath>
+#include <limits>
 #include <sstream>
 #include <tuple>
 
@@ -32,7 +30,7 @@ namespace fp_formatting {
  * assert(buffer[1] == '2');
  * assert(buffer[2] == '3');
  */
-inline int ConvertToChars(char* begin, char* end, size_t value, int width=1) {
+int ConvertToChars(char* begin, char* end, size_t value, int width=1) {
   assert(width >= 1);
   assert(end >= begin);     // end must be after begin
   assert(end-begin >= width); // Buffer must be large enough
@@ -184,24 +182,26 @@ std::string FpToString(T v, int precision = 0) {
 }
 }
 
-inline std::string FpToString(float v, size_t precision = 0) {
+std::string FpToString(float v, size_t precision) {
   return detail::fp_formatting::FpToString(v, precision);
 }
 
-inline std::string FpToString(double v, size_t precision = 0) {
+std::string FpToString(double v, size_t precision) {
   return detail::fp_formatting::FpToString(v, precision);
 }
 
 /**
  * dragonbox only works for floats/doubles not long double
  */
-inline std::string FpToString(long double v, size_t precision = std::numeric_limits<long double>::max_digits10) {
+std::string FpToString(long double v, size_t precision) {
   std::stringstream ss;
   ss.imbue(std::locale("C"));
+  if (precision == 0) {
+     precision = std::numeric_limits<long double>::max_digits10;
+  }
   ss.precision(precision);
   ss << v;
   return ss.str();
 }
 
 }
-#endif
diff --git a/test/fp_to_string_test.cpp b/test/fptostring_test.cpp
similarity index 99%
rename from test/fp_to_string_test.cpp
rename to test/fptostring_test.cpp
index 416cdfd..3f377ab 100644
--- a/test/fp_to_string_test.cpp
+++ b/test/fptostring_test.cpp
@@ -1,4 +1,4 @@
-#include "yaml-cpp/fp_to_string.h"
+#include "yaml-cpp/fptostring.h"
 #include "gtest/gtest.h"
 
 namespace YAML {