diff --git a/library/x509.c b/library/x509.c
index 093a315..65f2ec6 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -176,7 +176,7 @@
         return( MBEDTLS_ERR_X509_INVALID_ALG +
                 MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
 
-    p = (unsigned char *) alg->p;
+    p = alg->p;
     end = p + alg->len;
 
     if( p >= end )