diff --git a/tests/scripts/basic-build-test.sh b/tests/scripts/basic-build-test.sh
index 844c278..639a349 100755
--- a/tests/scripts/basic-build-test.sh
+++ b/tests/scripts/basic-build-test.sh
@@ -83,6 +83,11 @@
 : ${GNUTLS_LEGACY_CLI:="$GNUTLS_CLI"}
 : ${GNUTLS_LEGACY_SERV:="$GNUTLS_SERV"}
 
+# Used to make ssl-opt.sh deterministic.
+# !!! Keep this in sync with RELEASE_SEED in all.sh !!!
+: ${SEED:=1}
+export SEED
+
 # To avoid setting OpenSSL and GnuTLS for each call to compat.sh and ssl-opt.sh
 # we just export the variables they require
 export OPENSSL_CMD="$OPENSSL"