diff --git a/Makefile b/Makefile
index 044e6455c..c7f4c78cb 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,7 @@
+# This file is generated by tools/dmake, do not edit.
+
 ifndef CXXFLAGS
-    CXXFLAGS=-O2 -DNDEBUG -Wall
+    CXXFLAGS=-Wall -Wextra -Wshadow -pedantic -Wno-long-long -Wfloat-equal -Wcast-qual -Wsign-conversion -g
 endif
 
 ifndef CXX