diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index c1b3810..a37a077 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -74,10 +74,10 @@
 {
     int server_port;            /* port on which the ssl service runs       */
     int debug_level;            /* level of debugging                       */
-    char *ca_file;              /* the file with the CA certificate(s)      */
-    char *ca_path;              /* the path with the CA certificate(s) reside */
-    char *crt_file;             /* the file with the client certificate     */
-    char *key_file;             /* the file with the client key             */
+    const char *ca_file;        /* the file with the CA certificate(s)      */
+    const char *ca_path;        /* the path with the CA certificate(s) reside */
+    const char *crt_file;       /* the file with the client certificate     */
+    const char *key_file;       /* the file with the client key             */
     int force_ciphersuite[2];   /* protocol/ciphersuite to use, or all      */
     int renegotiation;          /* enable / disable renegotiation           */
     int allow_legacy;           /* allow legacy renegotiation               */
@@ -236,7 +236,7 @@
     int listen_fd;
     int client_fd = -1;
     unsigned char buf[1024];
-    char *pers = "ssl_server2";
+    const char *pers = "ssl_server2";
 
     entropy_context entropy;
     ctr_drbg_context ctr_drbg;
@@ -380,7 +380,8 @@
 
     entropy_init( &entropy );
     if( ( ret = ctr_drbg_init( &ctr_drbg, entropy_func, &entropy,
-                               (unsigned char *) pers, strlen( pers ) ) ) != 0 )
+                               (const unsigned char *) pers,
+                               strlen( pers ) ) ) != 0 )
     {
         printf( " failed\n  ! ctr_drbg_init returned -0x%x\n", -ret );
         goto exit;
@@ -402,7 +403,7 @@
     else 
 #endif
 #if defined(POLARSSL_CERTS_C)
-        ret = x509parse_crt( &cacert, (unsigned char *) test_ca_crt,
+        ret = x509parse_crt( &cacert, (const unsigned char *) test_ca_crt,
                 strlen( test_ca_crt ) );
 #else
     {
@@ -430,7 +431,7 @@
     else 
 #endif
 #if defined(POLARSSL_CERTS_C)
-        ret = x509parse_crt( &srvcert, (unsigned char *) test_srv_crt,
+        ret = x509parse_crt( &srvcert, (const unsigned char *) test_srv_crt,
                 strlen( test_srv_crt ) );
 #else
     {
@@ -450,7 +451,7 @@
     else
 #endif
 #if defined(POLARSSL_CERTS_C)
-        ret = x509parse_key( &rsa, (unsigned char *) test_srv_key,
+        ret = x509parse_key( &rsa, (const unsigned char *) test_srv_key,
                 strlen( test_srv_key ), NULL, 0 );
 #else
     {