diff --git a/library/rsa.c b/library/rsa.c
index d0a2695..b6fea49 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -1229,6 +1229,16 @@
 }
 
 /*
+ * This function is identical to mbedtls_mpi_exp_mod() the only difference is that this function is
+ * not constant time.
+ *
+ * WARNING! This function is not constant time.
+ */
+int mbedtls_mpi_exp_mod_unsafe(mbedtls_mpi *X, const mbedtls_mpi *A,
+                               const mbedtls_mpi *E, const mbedtls_mpi *N,
+                               mbedtls_mpi *prec_RR);
+
+/*
  * Do an RSA public key operation
  */
 int mbedtls_rsa_public(mbedtls_rsa_context *ctx,