--- a/netwerk/srtp/src/crypto/kernel/crypto_kernel.c
+++ b/netwerk/srtp/src/crypto/kernel/crypto_kernel.c
@@ -65,37 +65,37 @@ extern srtp_debug_module_t srtp_mod_auth
 extern srtp_debug_module_t srtp_mod_cipher;
 extern srtp_debug_module_t mod_stat;
 extern srtp_debug_module_t mod_alloc;
 
 /*
  * cipher types that can be included in the kernel
  */
 
-extern srtp_cipher_type_t srtp_null_cipher;
-extern srtp_cipher_type_t srtp_aes_icm_128;
-extern srtp_cipher_type_t srtp_aes_icm_256;
+extern const srtp_cipher_type_t srtp_null_cipher;
+extern const srtp_cipher_type_t srtp_aes_icm_128;
+extern const srtp_cipher_type_t srtp_aes_icm_256;
 #ifdef OPENSSL
 extern srtp_cipher_type_t srtp_aes_icm_192;
 extern srtp_cipher_type_t srtp_aes_gcm_128_openssl;
 extern srtp_cipher_type_t srtp_aes_gcm_256_openssl;
 #endif
 
 /* debug modules for cipher types */
 extern srtp_debug_module_t srtp_mod_aes_icm;
 #ifdef OPENSSL
 extern srtp_debug_module_t srtp_mod_aes_gcm;
 #endif
 
 /*
  * auth func types that can be included in the kernel
  */
 
-extern srtp_auth_type_t srtp_null_auth;
-extern srtp_auth_type_t srtp_hmac;
+extern const srtp_auth_type_t srtp_null_auth;
+extern const srtp_auth_type_t srtp_hmac;
 
 /* debug modules for auth types */
 extern srtp_debug_module_t srtp_mod_hmac;
 
 /* crypto_kernel is a global variable, the only one of its datatype */
 
 srtp_crypto_kernel_t crypto_kernel = {
     srtp_crypto_kernel_state_insecure, /* start off in insecure state */