diff --git a/Library/Homebrew/formula_creator.rb b/Library/Homebrew/formula_creator.rb
index 85a2e7c3f5..06ce159785 100644
--- a/Library/Homebrew/formula_creator.rb
+++ b/Library/Homebrew/formula_creator.rb
@@ -167,7 +167,7 @@ module Homebrew
         <% elsif mode == :python %>
             virtualenv_install_with_resources
         <% elsif mode == :rust %>
-            system "cargo", "install", "--root", prefix, "--path", "."
+            system "cargo", "install", "--locked", "--root", prefix, "--path", "."
         <% else %>
             # Remove unrecognized options if warned by configure
             system "./configure", "--disable-debug",