diff --git a/http/http_body.hpp b/http/http_body.hpp
index 46070cc..f4bfed5 100644
--- a/http/http_body.hpp
+++ b/http/http_body.hpp
@@ -178,7 +178,11 @@
 
     value_type& body;
     size_t sent = 0;
-    constexpr static size_t readBufSize = 4096;
+    // 64KB This number is arbitrary, and selected to try to optimize for larger
+    // files and fewer loops over per-connection reduction in memory usage.
+    // Nginx uses 16-32KB here, so we're in the range of what other webservers
+    // do.
+    constexpr static size_t readBufSize = 1024UL * 64UL;
     std::array<char, readBufSize> fileReadBuf{};
 
   public: