diff --git a/README.md b/README.md
index 2bf3cf5c4c..93886d6a11 100644
--- a/README.md
+++ b/README.md
@@ -47,10 +47,14 @@ Install prerequisite packages:
 
     sudo apt-get install libswsscommon libswsscommon-dev
 
+Before compiling, you will need to set an environmental variable to indicate which 'SAI flavor' you are using.
+
+    export DEB_SAI_FLAVOR=[FLAVOR]
+
 You can compile and install from source using:
 
     ./autogen.sh
-    ./configure
+    ./configure --with-sai=$(DEB_SAI_FLAVOR)
     make && sudo make install
 
 You can also build a debian package using: