diff --git a/README.md b/README.md
index 566b208..894e032 100644
--- a/README.md
+++ b/README.md
@@ -2,3 +2,4 @@ norvig-sudoku
 =============
 
 Norvig's Sudoku solver in C++ (English & Spanish versions).
+Compile with `--std=c++0x`.