diff --git a/Library/Homebrew/dev-cmd/update-license-data.rb b/Library/Homebrew/dev-cmd/update-license-data.rb
index 952a46ee27..456a7b38ec 100644
--- a/Library/Homebrew/dev-cmd/update-license-data.rb
+++ b/Library/Homebrew/dev-cmd/update-license-data.rb
@@ -16,8 +16,8 @@ module Homebrew
 
          Update SPDX license data in the Homebrew repository.
       EOS
-      switch "--fail-if-changed",
-             description: "Return a failing status code if current license data's version is different from " \
+      switch "--fail-if-not-changed",
+             description: "Return a failing status code if current license data's version is the same as " \
                           "the upstream. This can be used to notify CI when the SPDX license data is out of date."
       switch "--commit",
              description: "Commit changes to the SPDX license data."
@@ -33,7 +33,7 @@ module Homebrew
     data_url = "https://raw.githubusercontent.com/spdx/license-list-data/#{latest_tag}/json/licenses.json"
     curl_download(data_url, to: SPDX_PATH, partial: false)
 
-    Homebrew.failed = !system("git", "diff", "--stat", "--exit-code", SPDX_PATH) if args.fail_if_changed?
+    Homebrew.failed = system("git", "diff", "--stat", "--exit-code", SPDX_PATH) if args.fail_if_not_changed?
 
     return unless args.commit?
 
diff --git a/docs/Manpage.md b/docs/Manpage.md
index a41eb26a2f..192e877410 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -1052,8 +1052,8 @@ directory.
 
  Update SPDX license data in the Homebrew repository.
 
-* `--fail-if-changed`:
-  Return a failing status code if current license data's version is different from the upstream. This can be used to notify CI when the SPDX license data is out of date.
+* `--fail-if-not-changed`:
+  Return a failing status code if current license data's version is the same as the upstream. This can be used to notify CI when the SPDX license data is out of date.
 * `--commit`:
   Commit changes to the SPDX license data.
 
diff --git a/manpages/brew.1 b/manpages/brew.1
index 25e5ce2cc4..d0e45e813a 100644
--- a/manpages/brew.1
+++ b/manpages/brew.1
@@ -1361,8 +1361,8 @@ Initialise a Git repository in the unpacked source\. This is useful for creating
 Update SPDX license data in the Homebrew repository\.
 .
 .TP
-\fB\-\-fail\-if\-changed\fR
-Return a failing status code if current license data\'s version is different from the upstream\. This can be used to notify CI when the SPDX license data is out of date\.
+\fB\-\-fail\-if\-not\-changed\fR
+Return a failing status code if current license data\'s version is the same as the upstream\. This can be used to notify CI when the SPDX license data is out of date\.
 .
 .TP
 \fB\-\-commit\fR