diff --git a/include/chat/crypto.h b/include/chat/crypto.h
index 005e9b4..affdda5 100644
--- a/include/chat/crypto.h
+++ b/include/chat/crypto.h
@@ -23,6 +23,8 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 extern "C" {
 #endif
 
+#include <openssl/types.h>
+
 #include <why2/flags.h>
 
 #include <why2/chat/config.h>
@@ -39,7 +41,7 @@ void why2_chat_init_keys(void); //INIT (POSSIBLY GENERATE) ECC KEYS
 void why2_chat_deallocate_keys(void); //DEALLOCATE :) (NO SLUR HERE)
 
 char *why2_chat_ecc_sign(char *message); //SIGN message WITH ECC KEY
-why2_bool why2_chat_ecc_verify_signature(char *message, char *signature);
+why2_bool why2_chat_ecc_verify_signature(char *message, char *signature, EVP_PKEY *key);
 
 char *why2_sha256(char *input); //HASH input USING SHA256 AND RETURN IN STRING