diff --git a/README.md b/README.md
index 23cb2c1..4a8e9d9 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,7 @@
   1. We only develop on Ubuntu Linux. You may or may not have success on other
   systems.
   2. Python 2.7
+  3. libstdc++
 
 ## One-time setup
 * Fetch the code, for example via