diff --git a/src/option.c b/src/option.c
index 2f1ef11..bf65556 100644
--- a/src/option.c
+++ b/src/option.c
@@ -11452,6 +11452,7 @@
 
 /*
  * Return TRUE when option "name" has been set.
+ * Only works correctly for global options.
  */
     int
 option_was_set(name)