diff --git a/format.cc b/format.cc
index 288515aa..2b45fcc8 100644
--- a/format.cc
+++ b/format.cc
@@ -100,56 +100,6 @@ inline int FMT_SNPRINTF(char *buffer, size_t size, const char *format, ...) {
 #endif  // _MSC_VER
 
 const char RESET_COLOR[] = "\x1b[0m";
-
-void FormatSystemErrorMessage(
-    fmt::Writer &out, int error_code, fmt::StringRef message) {
-  fmt::internal::Array<char, fmt::internal::INLINE_BUFFER_SIZE> buffer;
-  buffer.resize(fmt::internal::INLINE_BUFFER_SIZE);
-  char *system_message = 0;
-  for (;;) {
-    system_message = &buffer[0];
-    int result = fmt::internal::StrError(
-        error_code, system_message, buffer.size());
-    if (result == 0)
-      break;
-    if (result != ERANGE) {
-      // Can't get error message, report error code instead.
-      out << message << ": error code = " << error_code;
-      return;
-    }
-    buffer.resize(buffer.size() * 2);
-  }
-  out << message << ": " << system_message;
-}
-
-#ifdef _WIN32
-void FormatWinErrorMessage(
-    fmt::Writer &out, int error_code, fmt::StringRef message) {
-  class String {
-   private:
-    LPWSTR str_;
-
-   public:
-    String() : str_() {}
-    ~String() { LocalFree(str_); }
-    LPWSTR *ptr() { return &str_; }
-    LPCWSTR c_str() const { return str_; }
-  };
-  String system_message;
-  if (FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
-      FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, 0,
-      error_code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-      reinterpret_cast<LPWSTR>(system_message.ptr()), 0, 0)) {
-    fmt::internal::UTF16ToUTF8 utf8_message;
-    if (!utf8_message.Convert(system_message.c_str())) {
-      out << message << ": " << fmt::c_str(utf8_message);
-      return;
-    }
-  }
-  // Can't get error message, report error code instead.
-  out << message << ": error code = " << error_code;
-}
-#endif
 }
 
 template <typename T>
@@ -277,6 +227,55 @@ int fmt::internal::StrError(
   return result;
 }
 
+void fmt::internal::FormatSystemErrorMessage(
+    fmt::Writer &out, int error_code, fmt::StringRef message) {
+  Array<char, INLINE_BUFFER_SIZE> buffer;
+  buffer.resize(INLINE_BUFFER_SIZE);
+  char *system_message = 0;
+  for (;;) {
+    system_message = &buffer[0];
+    int result = StrError(error_code, system_message, buffer.size());
+    if (result == 0)
+      break;
+    if (result != ERANGE) {
+      // Can't get error message, report error code instead.
+      out << message << ": error code = " << error_code;
+      return;
+    }
+    buffer.resize(buffer.size() * 2);
+  }
+  out << message << ": " << system_message;
+}
+
+#ifdef _WIN32
+void fmt::internal::FormatWinErrorMessage(
+    fmt::Writer &out, int error_code, fmt::StringRef message) {
+  class String {
+   private:
+    LPWSTR str_;
+
+   public:
+    String() : str_() {}
+    ~String() { LocalFree(str_); }
+    LPWSTR *ptr() { return &str_; }
+    LPCWSTR c_str() const { return str_; }
+  };
+  String system_message;
+  if (FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+      FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, 0,
+      error_code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+      reinterpret_cast<LPWSTR>(system_message.ptr()), 0, 0)) {
+    UTF16ToUTF8 utf8_message;
+    if (!utf8_message.Convert(system_message.c_str())) {
+      out << message << ": " << c_str(utf8_message);
+      return;
+    }
+  }
+  // Can't get error message, report error code instead.
+  out << message << ": error code = " << error_code;
+}
+#endif
+
 // Fills the padding around the content and returns the pointer to the
 // content area.
 template <typename Char>
@@ -805,14 +804,14 @@ void fmt::BasicWriter<Char>::FormatParser::Format(
 
 void fmt::SystemErrorSink::operator()(const fmt::Writer &w) const {
   Writer message;
-  FormatSystemErrorMessage(message, error_code_, w.c_str());
+  internal::FormatSystemErrorMessage(message, error_code_, w.c_str());
   throw SystemError(message.c_str(), error_code_);
 }
 
 #ifdef _WIN32
 void fmt::WinErrorSink::operator()(const Writer &w) const {
   Writer message;
-  FormatWinErrorMessage(message, error_code_, w.c_str());
+  internal::FormatWinErrorMessage(message, error_code_, w.c_str());
   throw SystemError(message.c_str(), error_code_);
 }
 #endif
diff --git a/format.h b/format.h
index 778aa769..07066392 100644
--- a/format.h
+++ b/format.h
@@ -500,6 +500,14 @@ class UTF16ToUTF8 {
 // Buffer should be at least of size 1.
 int StrError(int error_code, char *&buffer, std::size_t buffer_size);
 
+void FormatSystemErrorMessage(
+    fmt::Writer &out, int error_code, fmt::StringRef message);
+
+#ifdef _WIN32
+void FormatWinErrorMessage(
+    fmt::Writer &out, int error_code, fmt::StringRef message);
+#endif
+
 }  // namespace internal
 
 /**