diff --git a/conf/build.conf b/conf/build.conf
index 90ab6ae..1ff1e5f 100644
--- a/conf/build.conf
+++ b/conf/build.conf
@@ -26,7 +26,7 @@ dev {
 	# These flags are added to the shared ones when
 	# you build the "dev" flavor.
 	ldflags=-llua5.1
-	cflags=-g -Wextra
+	cflags=-g -Wall -Wextra -Werror
 	cflags=-I/usr/include/lua5.1
 	cxxflags=-g -Wextra
 }