diff --git a/archbuild.in b/archbuild.in
index 92d2554..5b5ab21 100644
--- a/archbuild.in
+++ b/archbuild.in
@@ -58,6 +58,13 @@ if ${clean_first} || [[ ! -d "${chroots}/${repo}-${arch}" ]]; then
 		-M "@pkgdatadir@/makepkg-${arch}.conf" \
 		"${chroots}/${repo}-${arch}/root" \
 		"${base_packages[@]}"
+
+	# FIXME: temporary workaround until pacman 4.0 moves to [core]
+	case $repo in
+		core|extra|community|multilib)
+			sed -r '/^SigLevel.*/d' -i "${chroots}/${repo}-${arch}/root/etc/pacman.conf"
+		;;
+	esac
 else
 	setarch ${arch} mkarchroot \
 		-u \
diff --git a/pacman-extra.conf b/pacman-extra.conf
index cdad265..828e2bd 100644
--- a/pacman-extra.conf
+++ b/pacman-extra.conf
@@ -46,7 +46,7 @@ Architecture = auto
 # If you wish to check signatures but avoid local sign and trust issues, use
 # the following line. This will treat any key imported into pacman's keyring as
 # trusted.
-SigLevel = Optional TrustAll
+#SigLevel = Optional TrustAll
 # Disable signature checks for now
 SigLevel = Never