diff --git a/util/build.sh b/util/build.sh
index 51c2c5687..2cf7934b0 100755
--- a/util/build.sh
+++ b/util/build.sh
@@ -127,11 +127,11 @@ as --version | tail -n1
 ld -v
 autoconf --version
 
-HOST="$HOST" BUILD="$BUILD" "$MAKE" "$@" -C ./depends/ V=1
+HOST="$HOST" BUILD="$BUILD" "$MAKE" CPPFLAGS='-std=gnu17' "$@" -C ./depends/ V=1
 
 time ./autogen.sh
 
-CONFIG_SITE="$PWD/depends/$HOST/share/config.site" ./configure "$HARDENING_ARG" "$LCOV_ARG" "$TEST_ARG" "$MINING_ARG" $CONFIGURE_FLAGS CXXFLAGS='-g'
+CONFIG_SITE="$PWD/depends/$HOST/share/config.site" ./configure "$HARDENING_ARG" "$LCOV_ARG" "$TEST_ARG" "$MINING_ARG" $CONFIGURE_FLAGS CXXFLAGS='-g' CPPFLAGS='-std=gnu17'
 
 # Build CryptoConditions stuff
 WD=$PWD