diff --git a/Library/Homebrew/formulary.rb b/Library/Homebrew/formulary.rb
index 8135629707..52728158a5 100644
--- a/Library/Homebrew/formulary.rb
+++ b/Library/Homebrew/formulary.rb
@@ -620,8 +620,8 @@ module Formulary
         path_realpath = path.realpath.to_s
         path_string = path.to_s
         if (path_realpath.end_with?(".rb") || path_string.end_with?(".rb")) &&
-           !path_realpath.start_with?("#{HOMEBREW_CELLAR}/", "#{HOMEBREW_LIBRARY}/Taps/", "#{HOMEBREW_CACHE}/") &&
-           !path_string.start_with?("#{HOMEBREW_CELLAR}/", "#{HOMEBREW_LIBRARY}/Taps/", "#{HOMEBREW_CACHE}/")
+           !path_realpath.start_with?("#{HOMEBREW_CELLAR}/", "#{HOMEBREW_LIBRARY}/Taps/") &&
+           !path_string.start_with?("#{HOMEBREW_CELLAR}/", "#{HOMEBREW_LIBRARY}/Taps/")
           if path_string.include?("./") || path_string.end_with?(".rb") || path_string.count("/") != 2
             raise <<~WARNING
               Homebrew requires formulae to be in a tap, rejecting:
diff --git a/Library/Homebrew/test/formulary_spec.rb b/Library/Homebrew/test/formulary_spec.rb
index 3ab0bafb71..0f957e23e4 100644
--- a/Library/Homebrew/test/formulary_spec.rb
+++ b/Library/Homebrew/test/formulary_spec.rb
@@ -141,19 +141,26 @@ RSpec.describe Formulary do
         end.to raise_error(FormulaUnavailableError)
       end
 
-      it "allows cache paths even when paths are disabled" do
-        ENV["HOMEBREW_FORBID_PACKAGES_FROM_PATHS"] = "1"
-        cache_dir = HOMEBREW_CACHE/"test_formula_cache"
-        cache_dir.mkpath
-        cache_formula_path = cache_dir/formula_path.basename
-        FileUtils.cp formula_path, cache_formula_path
-        begin
-          formula = described_class.factory(cache_formula_path)
-          expect(formula).to be_a(Formula)
-        ensure
+      context "when given a cache path" do
+        let(:cache_dir) { HOMEBREW_CACHE/"test_formula_cache" }
+        let(:cache_formula_path) { cache_dir/formula_path.basename }
+
+        before do
+          cache_dir.mkpath
+          FileUtils.cp formula_path, cache_formula_path
+        end
+
+        after do
           cache_formula_path.unlink if cache_formula_path.exist?
           cache_dir.rmdir if cache_dir.exist?
         end
+
+        it "disallows cache paths when paths are explicitly disabled" do
+          ENV["HOMEBREW_FORBID_PACKAGES_FROM_PATHS"] = "1"
+          expect do
+            described_class.factory(cache_formula_path)
+          end.to raise_error(/requires formulae to be in a tap/)
+        end
       end
 
       context "when given a bottle" do