diff --git a/fmt/format.h b/fmt/format.h
index b4283853..bcfb7c29 100644
--- a/fmt/format.h
+++ b/fmt/format.h
@@ -3320,7 +3320,7 @@ void BasicWriter<Char>::write_double(T value, const Spec &spec) {
   accessed as a C string with ``out.c_str()``.
   \endrst
  */
-template <typename Char, typename Allocator = std::allocator<Char> ,std::size_t INLINE_BUFFER_SIZE = internal::INLINE_BUFFER_SIZE>
+template <typename Char, typename Allocator = std::allocator<Char>, std::size_t INLINE_BUFFER_SIZE = internal::INLINE_BUFFER_SIZE>
 class BasicMemoryWriter : public BasicWriter<Char> {
  private:
   internal::MemoryBuffer<Char, INLINE_BUFFER_SIZE, Allocator> buffer_;