diff --git a/cpp/Makefile b/cpp/Makefile
index 50c8770..c1e549a 100644
--- a/cpp/Makefile
+++ b/cpp/Makefile
@@ -1,3 +1,5 @@
+CXXFLAGS += -O3 -Wall
+
 # Add .d to Make's recognized suffixes.
 SUFFIXES += .d