diff --git a/library/x509.c b/library/x509.c
index 13081e3..49f7672 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -876,7 +876,7 @@
     ((void) sig_opts);
 #endif /* POLARSSL_X509_RSASSA_PSS_SUPPORT */
 
-    return( (int) size - n );
+    return( (int)( size - n ) );
 }
 
 /*