diff --git a/extras/build-tests/nix/build b/extras/build-tests/nix/build
index 14e2123f9..33f845fec 100755
--- a/extras/build-tests/nix/build
+++ b/extras/build-tests/nix/build
@@ -23,14 +23,8 @@ export CPPFLAGS="$CPPFLAGS -DFAKELAG_CONFIGURABLE -DNOREMOVETMP -DTESTSUITE"
 # !! temporary use this:
 cp extras/build-tests/nix/configs/default ./config.settings
 
-# Debian 8 workaround:
-if lsb_release -av 2>&1|egrep 'Debian.*jessie'; then
-	echo "Disabling ASan due to false positives on deb8"
-	echo 'EXTRAPARA="--enable-werror --disable-asan"' >>config.settings
-fi
-if uname -s|grep -i freebsd; then
-	echo "Disabling ASan on FreeBSD due to 100% CPU loop in OpenSSL initialization routine"
-	echo 'EXTRAPARA="--enable-werror --disable-asan"' >>config.settings
+if [ "$USE_SHIPPED_LIBS" = "1" ]; then
+    echo 'EXTRAPARA="--enable-werror --without-system-pcre2 --without-system-argon2 --without-system-sodium --without-system-cares --without-system-jansson"' >>config.settings
 fi
 
 # If SSLDIR is set the environment, this overrides config.settings