diff --git a/library/x509write_csr.c b/library/x509write_csr.c
index 0c3c396..7c51798 100644
--- a/library/x509write_csr.c
+++ b/library/x509write_csr.c
@@ -214,7 +214,9 @@
         return( MBEDTLS_ERR_X509_FATAL_ERROR );
     }
 #else /* MBEDTLS_USE_PSA_CRYPTO */
-    mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c, len, hash );
+    ret = mbedtls_md( mbedtls_md_info_from_type( ctx->md_alg ), c, len, hash );
+    if( ret != 0 )
+        return( ret );
 #endif
     if( ( ret = mbedtls_pk_sign( ctx->key, ctx->md_alg, hash, 0, sig, &sig_len,
                                  f_rng, p_rng ) ) != 0 )