diff --git a/lfs/bc-7.0.3.PKGBUILD b/lfs/bc-7.0.3.PKGBUILD
index 176bb1c..491aa22 100644
--- a/lfs/bc-7.0.3.PKGBUILD
+++ b/lfs/bc-7.0.3.PKGBUILD
@@ -15,6 +15,7 @@ src_prepare() {
 
 src_build() {
   CFLAGS+=" -O3 -flto -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing"       \
+  CFLAGS+=" -std=gnu17" # fix bug
   CC=gcc    \
   ./configure --prefix=/usr -G -r
   make