diff --git a/ssl/tls13_enc.c b/ssl/tls13_enc.c
index 910336281d3a7bdb36b725d9cf608bfa6f41ccf4..3b783a74af59899f8cd058fce3915420f9e89a3d 100644
--- a/ssl/tls13_enc.c
+++ b/ssl/tls13_enc.c
@@ -124,7 +124,7 @@ int tls13_generate_secret(SSL *s, const EVP_MD *md,
     size_t mdlen, prevsecretlen;
     int ret;
     EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_HKDF, NULL);
-    const char *derived_secret_label = "derived secret";
+    static const char derived_secret_label[] = "derived secret";
     unsigned char preextractsec[EVP_MAX_MD_SIZE];
 
     if (pctx == NULL)