diff --git a/src/xdiff/xdiffi.h b/src/xdiff/xdiffi.h
index 8f1c7c8..467a1e8 100644
--- a/src/xdiff/xdiffi.h
+++ b/src/xdiff/xdiffi.h
@@ -61,4 +61,4 @@
 int xdl_do_histogram_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
 		xdfenv_t *env);
 
-#endif /* #if !defined(XDIFFI_H) */
+#endif // #if !defined(XDIFFI_H)