diff --git a/library/ecdsa.c b/library/ecdsa.c
old mode 100644
new mode 100755
index 6411a5e..2daabee
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -266,7 +266,7 @@
     if( grp->id == MBEDTLS_ECP_DP_CURVE25519 ||
         grp->id == MBEDTLS_ECP_DP_CURVE448 ||
         grp->N.p == NULL )
-        return( MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE );
+        return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
 
     /* Make sure d is in range 1..n-1 */
     if( mbedtls_mpi_cmp_int( d, 1 ) < 0 || mbedtls_mpi_cmp_mpi( d, &grp->N ) >= 0 )