diff --git a/format-test.cc b/format-test.cc
index c5be9030..a1f55496 100644
--- a/format-test.cc
+++ b/format-test.cc
@@ -1555,6 +1555,11 @@ TEST(FormatterTest, FormatExamples) {
     std::string s = writer.str(); // s == 0123456789
     EXPECT_EQ("0123456789", s);
   }
+
+  const char *filename = "nonexistent";
+  FILE *f = fopen(filename, "r");
+  if (!f)
+    fmt::ThrowSystemError(errno, "Cannot open file '{}'") << filename;
 }
 
 TEST(FormatterTest, StrNamespace) {
@@ -1653,7 +1658,7 @@ TEST(FormatterTest, FileSinkWriteError) {
   std::fclose(f);
 }
 
-// TODO: test SystemErrorSink, ThrowSystemError, CErrorSink, ThrowCError.
+// TODO: test SystemErrorSink, ThrowSystemError, CErrorSink, ThrowWinError.
 
 // The test doesn't compile on older compilers which follow C++03 and
 // require an accessible copy constructor when binding a temporary to
diff --git a/format.cc b/format.cc
index 3dc7a083..288515aa 100644
--- a/format.cc
+++ b/format.cc
@@ -101,7 +101,7 @@ inline int FMT_SNPRINTF(char *buffer, size_t size, const char *format, ...) {
 
 const char RESET_COLOR[] = "\x1b[0m";
 
-void FormatCErrorMessage(
+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);
@@ -122,11 +122,9 @@ void FormatCErrorMessage(
   out << message << ": " << system_message;
 }
 
-void FormatSystemErrorMessage(
+#ifdef _WIN32
+void FormatWinErrorMessage(
     fmt::Writer &out, int error_code, fmt::StringRef message) {
-#ifndef _WIN32
-  FormatCErrorMessage(out, error_code, message);
-#else
   class String {
    private:
     LPWSTR str_;
@@ -150,8 +148,8 @@ void FormatSystemErrorMessage(
   }
   // Can't get error message, report error code instead.
   out << message << ": error code = " << error_code;
-#endif
 }
+#endif
 }
 
 template <typename T>
@@ -811,11 +809,13 @@ void fmt::SystemErrorSink::operator()(const fmt::Writer &w) const {
   throw SystemError(message.c_str(), error_code_);
 }
 
-void fmt::CErrorSink::operator()(const Writer &w) const {
+#ifdef _WIN32
+void fmt::WinErrorSink::operator()(const Writer &w) const {
   Writer message;
-  FormatCErrorMessage(message, error_code_, w.c_str());
+  FormatWinErrorMessage(message, error_code_, w.c_str());
   throw SystemError(message.c_str(), error_code_);
 }
+#endif
 
 void fmt::ANSITerminalSink::operator()(
     const fmt::BasicWriter<char> &w) const {
diff --git a/format.h b/format.h
index a8f9e62f..778aa769 100644
--- a/format.h
+++ b/format.h
@@ -1531,7 +1531,7 @@ inline Formatter<NullSink, wchar_t> Format(WStringRef format) {
 
 /**
   A sink that gets the error message corresponding to a system error code
-  and throws SystemError.
+  as given by errno and throws SystemError.
  */
 class SystemErrorSink {
  private:
@@ -1547,8 +1547,7 @@ class SystemErrorSink {
   Formats a message and throws SystemError with the description of the form
   "<message>: <system-message>", where <message> is the formatted message and
   <system-message> is the system message corresponding to the error code.
-  error_code is a system error code as given by errno for POSIX and
-  GetLastError for Windows.
+  error_code is a system error code as given by errno.
  */
 inline Formatter<SystemErrorSink> ThrowSystemError(
     int error_code, StringRef format) {
@@ -1557,15 +1556,15 @@ inline Formatter<SystemErrorSink> ThrowSystemError(
 }
 
 /**
-  A sink that gets the error message corresponding to a standard C library
-  error code as given by errno and throws SystemError.
+  A sink that gets the error message corresponding to a Windows error code
+  as given by GetLastError and throws SystemError.
  */
-class CErrorSink {
+class WinErrorSink {
  private:
   int error_code_;
 
  public:
-  explicit CErrorSink(int error_code) : error_code_(error_code) {}
+  explicit WinErrorSink(int error_code) : error_code_(error_code) {}
 
   void operator()(const Writer &w) const;
 };
@@ -1574,11 +1573,10 @@ class CErrorSink {
   Formats a message and throws SystemError with the description of the form
   "<message>: <system-message>", where <message> is the formatted message and
   <system-message> is the system message corresponding to the error code.
-  error_code is an error code as given by errno after calling a C library
-  function.
+  error_code is a Windows error code as given by GetLastError.
  */
-inline Formatter<CErrorSink> ThrowCError(int error_code, StringRef format) {
-  Formatter<CErrorSink> f(format, CErrorSink(error_code));
+inline Formatter<WinErrorSink> ThrowWinError(int error_code, StringRef format) {
+  Formatter<WinErrorSink> f(format, WinErrorSink(error_code));
   return f;
 }
 
@@ -1593,7 +1591,7 @@ class FileSink {
   /** Writes the output to a file. */
   void operator()(const BasicWriter<char> &w) const {
     if (std::fwrite(w.data(), w.size(), 1, file_) == 0)
-      ThrowCError(errno, "cannot write to file");
+      ThrowSystemError(errno, "cannot write to file");
   }
 };