diff --git a/Library/Homebrew/bundle/brew_installer.rb b/Library/Homebrew/bundle/brew_installer.rb
index cf5112e53b..6efabb3267 100644
--- a/Library/Homebrew/bundle/brew_installer.rb
+++ b/Library/Homebrew/bundle/brew_installer.rb
@@ -61,11 +61,12 @@ module Homebrew
 
           if result && @version_file.present?
             # Use the version from the environment if it hasn't changed.
+            # Strip the revision number because it's not part of the non-Homebrew version.
             version = if !changed? && (env_version = Bundle.formula_versions_from_env[@name])
               env_version
             else
               Formula[@full_name].version.to_s
-            end
+            end.sub(/_\d+$/, "")
             version_path = Pathname.new(@version_file)
             version_path.write("#{version}\n")