diff --git a/format.h b/format.h
index a9d2311c..01d78e2e 100644
--- a/format.h
+++ b/format.h
@@ -1130,13 +1130,13 @@ for example a file opening error.
 */
 class SystemError : public internal::SystemErrorBase {
  private:
-  typedef char Char;  // For FMT_VARIADIC_CTOR.
-
   void init(int error_code, StringRef format_str, const ArgList &args);
 
  protected:
   int error_code_;
 
+  typedef char Char;  // For FMT_VARIADIC_CTOR.
+
   SystemError() {}
 
  public: