diff --git a/autogen.sh b/autogen.sh
index c431f6ad..3355396a 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -4,6 +4,7 @@ autoreconf -v -f --install "$(dirname "$0")" || exit 1
 
 CFLAGS="-O2"
 CFLAGS="$CFLAGS -Wall"
+CFLAGS="$CFLAGS -Wextra"
 CFLAGS="$CFLAGS -Werror=implicit-function-declaration"
 
 "$(dirname "$0")"/configure \