diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 865c73d42..e18d91a17 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -135,6 +135,14 @@ pre_initialize_variables () {
     FORCE=0
     KEEP_GOING=0
 
+    # Seed value used with the --release-test option.
+    #
+    # See also RELEASE_SEED in basic-build-test.sh. Debugging is easier if
+    # both values are kept in sync. If you change the value here because it
+    # breaks some tests, you'll definitely want to change it in
+    # basic-build-test.sh as well.
+    RELEASE_SEED=1
+
     : ${MBEDTLS_TEST_OUTCOME_FILE=}
     : ${MBEDTLS_TEST_PLATFORM="$(uname -s | tr -c \\n0-9A-Za-z _)-$(uname -m | tr -c \\n0-9A-Za-z _)"}
     export MBEDTLS_TEST_OUTCOME_FILE
@@ -232,7 +240,7 @@ General options:
      --outcome-file=<path>  File where test outcomes are written (not done if
                             empty; default: \$MBEDTLS_TEST_OUTCOME_FILE).
      --random-seed      Use a random seed value for randomized tests (default).
-  -r|--release-test     Run this script in release mode. This fixes the seed value to 1.
+  -r|--release-test     Run this script in release mode. This fixes the seed value to ${RELEASE_SEED}.
   -s|--seed             Integer seed value to use for this test run.
 
 Tool path options:
@@ -382,7 +390,7 @@ pre_parse_command_line () {
             --outcome-file) shift; MBEDTLS_TEST_OUTCOME_FILE="$1";;
             --out-of-source-dir) shift; OUT_OF_SOURCE_DIR="$1";;
             --random-seed) unset SEED;;
-            --release-test|-r) SEED=1;;
+            --release-test|-r) SEED=$RELEASE_SEED;;
             --seed|-s) shift; SEED="$1";;
             -*)
                 echo >&2 "Unknown option: $1"
diff --git a/tests/scripts/basic-build-test.sh b/tests/scripts/basic-build-test.sh
index 4fb924784..83646f361 100755
--- a/tests/scripts/basic-build-test.sh
+++ b/tests/scripts/basic-build-test.sh
@@ -56,6 +56,14 @@ fi
 : ${GNUTLS_LEGACY_CLI:="$GNUTLS_CLI"}
 : ${GNUTLS_LEGACY_SERV:="$GNUTLS_SERV"}
 
+# Used to make ssl-opt.sh deterministic.
+#
+# See also RELEASE_SEED in all.sh. Debugging is easier if both values are kept
+# in sync. If you change the value here because it breaks some tests, you'll
+# definitely want to change it in all.sh as well.
+: ${SEED:=1}
+export SEED
+
 # To avoid setting OpenSSL and GnuTLS for each call to compat.sh and ssl-opt.sh
 # we just export the variables they require
 export OPENSSL_CMD="$OPENSSL"