diff --git a/t/fusion.c b/t/fusion.c
index 905b6a4..934a492 100644
--- a/t/fusion.c
+++ b/t/fusion.c
@@ -470,7 +470,7 @@
  */
 static void test_generated_set_capacity(void)
 {
-    static const uint8_t secret[PTLS_MAX_DIGEST_SIZE] = "deadbeef", input[3000] = {};
+    static const uint8_t secret[PTLS_MAX_DIGEST_SIZE] = "deadbeef", input[3000] = {0};
     uint8_t encrypted[4000], decrypted[4000];
 
     ptls_aead_context_t *enc = ptls_aead_new(test_generated_encryptor, &ptls_minicrypto_sha256, 1, secret, ""),