diff --git a/include/polarssl/ecdsa.h b/include/polarssl/ecdsa.h
index 15b90e6..47382e5 100644
--- a/include/polarssl/ecdsa.h
+++ b/include/polarssl/ecdsa.h
@@ -143,6 +143,16 @@
                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
 
 /**
+ * \brief           Set an ECDSA context from an EC key pair
+ *
+ * \param ctx       ECDSA context to set
+ * \param key       EC key to use
+ *
+ * \return          0 on success, or a POLARSSL_ERR_ECP code.
+ */
+int ecdsa_from_keypair( ecdsa_context *ctx, const ecp_keypair *key );
+
+/**
  * \brief           Initialize context
  *
  * \param ctx       Context to initialize