diff --git a/squashfs-tools/action.h b/squashfs-tools/action.h
index 1ca2df1..e1be949 100644
--- a/squashfs-tools/action.h
+++ b/squashfs-tools/action.h
@@ -188,7 +188,7 @@
 
 /*
  * Action logging requested, specified by the various
- * -action, -true_action, -false_action and -verbose_action
+ * -action, -true-action, -false-action and -verbose-action
  * options
  */
 #define ACTION_LOG_NONE	0