diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 505bb6c..df7b734 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -49,8 +49,7 @@
 
 #include <string.h>
 
-#if defined(MBEDTLS_X509_CRT_PARSE_C) && \
-    defined(MBEDTLS_X509_CHECK_EXTENDED_KEY_USAGE)
+#if defined(MBEDTLS_X509_CRT_PARSE_C)
 #include "mbedtls/oid.h"
 #endif
 
@@ -4347,7 +4346,7 @@
 
         ret = mbedtls_x509_crt_parse_der( ssl->session_negotiate->peer_cert,
                                   ssl->in_msg + i, n );
-        if( ret != 0 )
+        if( 0 != ret && ( MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG + MBEDTLS_ERR_OID_NOT_FOUND ) != ret )
         {
             MBEDTLS_SSL_DEBUG_RET( 1, " mbedtls_x509_crt_parse_der", ret );
             return( ret );