diff --git a/library/ssl_tls13_keys.h b/library/ssl_tls13_keys.h
index 14f6e48..f6d02b5 100644
--- a/library/ssl_tls13_keys.h
+++ b/library/ssl_tls13_keys.h
@@ -40,8 +40,9 @@
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
 
+/* We need to tell the compiler that we meant to leave out the null character. */
 #define MBEDTLS_SSL_TLS1_3_LABEL(name, string)       \
-    const unsigned char name    [sizeof(string) - 1];
+    const unsigned char name    [sizeof(string) - 1] __attribute__ ((nonstring));
 
 union mbedtls_ssl_tls13_labels_union {
     MBEDTLS_SSL_TLS1_3_LABEL_LIST