diff --git a/autogen.sh b/autogen.sh
index 3355396a..07236426 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -6,6 +6,7 @@ CFLAGS="-O2"
 CFLAGS="$CFLAGS -Wall"
 CFLAGS="$CFLAGS -Wextra"
 CFLAGS="$CFLAGS -Werror=implicit-function-declaration"
+CFLAGS="$CFLAGS -Wno-expansion-to-defined"
 
 "$(dirname "$0")"/configure \
 	CFLAGS="$CFLAGS" \