diff --git a/README.md b/README.md
index 626b57a..d600225 100644
--- a/README.md
+++ b/README.md
@@ -388,7 +388,10 @@ it's very likely because all parsers need to check the first character by itself
 macros `FASTFLOAT_ONLY_ROUNDS_TO_NEAREST_SUPPORTED` if you only need `FE_TONEAREST` rounding mode in the parsing; this option
 also improves performance a bit and reduces code size. In the high-performance example, I also use the [fmt library](https://github.com/fmtlib/fmt), which also
 supports all C++ standards since C++11. I also recommend using `string_view` everywhere if it's possible; it's available
-since C++17, and if you want maximum performance, use the latest compiler with the latest C++ with O3 optimization and LTO!
+since C++17, and if you want maximum performance, use the latest compiler with the latest C++ with maximum optimization:
+```
+-O3 -DNDEBUG + LTO
+```
 ```C++
 #define FASTFLOAT_ONLY_POSITIVE_C_NUMBER_WO_INF_NAN
 #define FASTFLOAT_ISNOT_CHECKED_BOUNDS