diff --git a/README.md b/README.md
index 7188adf..158b175 100644
--- a/README.md
+++ b/README.md
@@ -124,7 +124,7 @@ Then, run `bin/rails tailwindcss:upgrade`. Among other things, this will try to
 - If present, moves `app/assets/stylesheets/application.tailwind.css` to `app/assets/tailwind/application.css`.
 - Removes unnecessary `stylesheet_link_tag "tailwindcss"` tags from the application layout.
 - Removes references to the Inter font from the application layout.
-- Runs the upstream upgrader (note: requires `npx` to run the one-time upgrade, but highly recommended).
+- Runs v4.1.4 of the upstream upgrader (note: requires `npx` to run the one-time upgrade, but highly recommended).
 
 </details>
 
@@ -145,7 +145,7 @@ $ bin/rails tailwindcss:upgrade
       remove    app/assets/stylesheets/application.tailwind.css
 10.9.0
   Running the upstream Tailwind CSS upgrader
-         run    npx @tailwindcss/upgrade --force --config /home/user/myapp/config/tailwind.config.js from "."
+         run    npx @tailwindcss/upgrade@4.1.4 --force --config /home/user/myapp/config/tailwind.config.js from "."
 ≈ tailwindcss v4.0.0
 │ Searching for CSS files in the current directory and its subdirectories…
 │ ↳ Linked `./config/tailwind.config.js` to `./app/assets/tailwind/application.css`
diff --git a/lib/install/upgrade_tailwindcss.rb b/lib/install/upgrade_tailwindcss.rb
index 004d9a8..d6ecada 100644
--- a/lib/install/upgrade_tailwindcss.rb
+++ b/lib/install/upgrade_tailwindcss.rb
@@ -45,8 +45,14 @@
 end
 
 if system("npx --version")
+  # We're pinning to v4.1.4 because v4.1.5 of the upgrade tool introduces a dependency version check
+  # on tailwind and I haven't been able to figure out how to get that to work reliably and I am
+  # extremely frustrated with the whole thing. See #544
+  #
+  # At some point we will probably need to unpin this at which point I am sincerely hoping that
+  # someone else will do it.
   say "Running the upstream Tailwind CSS upgrader"
-  command = Shellwords.join(["npx", "@tailwindcss/upgrade", "--force", "--config", TAILWIND_CONFIG_PATH.to_s])
+  command = Shellwords.join(["npx", "@tailwindcss/upgrade@4.1.4", "--force", "--config", TAILWIND_CONFIG_PATH.to_s])
   success = run(command, abort_on_failure: false)
   unless success
     say "The upgrade tool failed!", :red