diff --git a/tests/api.c b/tests/api.c
index 67bbe0406..1b24f23a5 100644
--- a/tests/api.c
+++ b/tests/api.c
@@ -9173,7 +9173,7 @@ static int test_tls_ext_duplicate(void)
 {
     int res = TEST_SKIPPED;
 #if !defined(NO_WOLFSSL_SERVER) && (!defined(NO_RSA) || defined(HAVE_ECC))
-    static unsigned char clientHelloDupTlsExt[] = {
+    const unsigned char clientHelloDupTlsExt[] = {
         0x16, 0x03, 0x03, 0x00, 0x6a, 0x01, 0x00, 0x00,
         0x66, 0x03, 0x03, 0xf4, 0x65, 0xbd, 0x22, 0xfe,
         0x6e, 0xab, 0x66, 0xdd, 0xcf, 0xe9, 0x65, 0x55,
@@ -9192,8 +9192,6 @@ static int test_tls_ext_duplicate(void)
         /* Supported Versions extension for TLS 1.3. */
                                             0x00, 0x2b,
         0x00, 0x05, 0x04, 0x03, 0x04, 0x03, 0x03
-        
-
     };
     WOLFSSL_BUFFER_INFO msg;
     const char* testCertFile;
@@ -9225,7 +9223,7 @@ static int test_tls_ext_duplicate(void)
     ssl = wolfSSL_new(ctx);
     AssertNotNull(ssl);
 
-    msg.buffer = clientHelloDupTlsExt;
+    msg.buffer = (unsigned char*)clientHelloDupTlsExt;
     msg.length = (unsigned int)sizeof(clientHelloDupTlsExt);
     wolfSSL_SetIOReadCtx(ssl, &msg);