diff --git a/README.md b/README.md
index 9637c409..9c7e19cb 100644
--- a/README.md
+++ b/README.md
@@ -317,8 +317,11 @@ A note on compilers; in general, foot runs **much** faster when
 compiled with gcc instead of clang. A profile-guided gcc build can be
 more than twice as fast as a clang build.
 
-**Note** GCC 10.1 has a performance regression that affects foot. A
-PGO build is about 30-40% slower with GCC 10.1 compared to GCC 9.3.
+**Note** GCC 10.1 has a performance regression that severely affects
+foot when doing PGO builds and building with `-O2`; it is about 30-40%
+slower compared to GCC 9.3.
+
+The work around is simple: make sure you build with `-O3`.
 
 
 ## Installing