diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 6114a8896c..e65b08adc3 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -2760,6 +2760,11 @@ class Formula
     def ignore_missing_libraries(*)
       raise FormulaSpecificationError, "#{__method__} is available on Linux only"
     end
+
+    # @private
+    def allowed_missing_libraries
+      raise NotImplementedError, "#{__method__} is available on Linux only"
+    end
   end
 end