diff --git a/README-English.md b/README-English.md
index 8b32f9bb..0ac319d1 100644
--- a/README-English.md
+++ b/README-English.md
@@ -135,7 +135,7 @@ USAGE:
     -v --verbose 'Output verbose information'
     -D --enable-deprecated-rules 'Enable sigma rules marked as deprecated'
     -n --enable-noisy-rules 'Enable rules marked as noisy'
-    -u --rule-update 'Clone latest hayabusa-rule'
+    -u --update-rules 'Clone latest hayabusa-rule'
     -m --min-level=[LEVEL] 'Minimum level for rules (default: informational)'
     --start-timeline=[STARTTIMELINE] 'Start time of the event to load from event file. Example: '2018/11/28 12:00:00 +09:00''
     --end-timeline=[ENDTIMELINE] 'End time of the event to load from event file. Example: '2018/11/28 12:00:00 +09:00''
diff --git a/README-Japanese.md b/README-Japanese.md
index 1e127b61..9291a5c0 100644
--- a/README-Japanese.md
+++ b/README-Japanese.md
@@ -129,7 +129,7 @@ USAGE:
     -v --verbose 'Output verbose information'
     -D --enable-deprecated-rules 'Enable sigma rules marked as deprecated'
     -n --enable-noisy-rules 'Enable rules marked as noisy'
-    -u --rule-update 'Clone latest hayabusa-rule'
+    -u --update-rules 'Clone latest hayabusa-rule'
     -m --min-level=[LEVEL] 'Minimum level for rules (default: informational)'
     --start-timeline=[STARTTIMELINE] 'Start time of the event to load from event file. Example: '2018/11/28 12:00:00 +09:00''
     --end-timeline=[ENDTIMELINE] 'End time of the event to load from event file. Example: '2018/11/28 12:00:00 +09:00''