diff --git a/t/lib-gpg.sh b/t/lib-gpg.sh
index f99ef3e859..4c549beba6 100644
--- a/t/lib-gpg.sh
+++ b/t/lib-gpg.sh
@@ -104,6 +104,12 @@ test_lazy_prereq GPGSSH '
 	test $? != 127 || exit 1
 	echo $ssh_version | grep -q "find-principals:missing signature file"
 	test $? = 0 || exit 1;
+
+	# some broken versions of ssh-keygen segfault on find-principals;
+	# avoid testing with them.
+	ssh-keygen -Y find-principals -f /dev/null -s /dev/null
+	test $? = 139 && exit 1
+
 	mkdir -p "${GNUPGHOME}" &&
 	chmod 0700 "${GNUPGHOME}" &&
 	ssh-keygen -t ed25519 -N "" -C "git ed25519 key" -f "${GPGSSH_KEY_PRIMARY}" >/dev/null &&