diff --git a/INSTALL.md b/INSTALL.md
index 9addb23..335be54 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -12,6 +12,13 @@ version. If your distro has 1.1, see if you can grab 1.0 or 1.0.1 in some way,
 either through the distro package or by downloading OpenSSL manually from its
 website, or some alternative package manager such as GNU Guix.
 
+UPDATE: If you proceed with the steps below and `stack build` throws an error
+while building `HsOpenSSL`, there's a chance you can still use OpenSSL 1.1
+successfully if you run these commands:
+
+    $ stack build HsOpenSSL --flag HsOpenSSL:-fast-bignum
+    $ stack build
+
 Install dependency library development packages. It's very likely you already
 have them all installed, and if you're missing some, the build process will
 inform you. But it's still nice to have a list here. The list below isn't a