diff --git a/INSTALL.md b/INSTALL.md
index 1b947549..df56d73a 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -127,10 +127,10 @@ mkdir -p bld/release && cd bld/release
 ### Release build
 
 ```sh
-CFLAGS+="-O3 -march=native -fno-plt"
-export CFLAGS
+export CFLAGS="$CFLAGS -O3 -march=native"
 meson --buildtype=release --prefix=/usr -Db_lto=true ../..
 ```
+Both `-O3` (in `CFLAGS`) and `-Db_lto=true` are **highly** recommended.
 
 For performance reasons, I strongly recommend doing a
 [PGO](#profile-guided-optimization) (Profile Guided Optimization)