diff --git a/Library/Homebrew/test/cmd/--prefix_spec.rb b/Library/Homebrew/test/cmd/--prefix_spec.rb
index 9ee10f6bef004..48efc0f51b070 100644
--- a/Library/Homebrew/test/cmd/--prefix_spec.rb
+++ b/Library/Homebrew/test/cmd/--prefix_spec.rb
@@ -13,7 +13,7 @@
       .and be_a_success
   end
 
-  it "prints the prefix for a Formula", :integration_test do
+  it "prints the prefix for a Formula", :integration_test, :needs_homebrew_core do
     expect { brew_sh "--prefix", "wget" }
       .to output("#{ENV.fetch("HOMEBREW_PREFIX")}/opt/wget\n").to_stdout
       .and not_to_output.to_stderr
diff --git a/Library/Homebrew/test/spec_helper.rb b/Library/Homebrew/test/spec_helper.rb
index 2dd6dc134d4b6..4287f45a1c340 100644
--- a/Library/Homebrew/test/spec_helper.rb
+++ b/Library/Homebrew/test/spec_helper.rb
@@ -160,6 +160,11 @@
     skip "Requires network connection." unless ENV["HOMEBREW_TEST_ONLINE"]
   end
 
+  config.before(:each, :needs_homebrew_core) do
+    core_tap_path = "#{ENV.fetch("HOMEBREW_LIBRARY")}/Taps/homebrew/homebrew-core"
+    skip "Requires homebrew/core to be tapped." unless Dir.exist?(core_tap_path)
+  end
+
   config.before do |example|
     next if example.metadata.key?(:needs_network)
     next if example.metadata.key?(:needs_utils_curl)
diff --git a/Library/Homebrew/test/support/helper/spec/shared_examples/formulae_exist.rb b/Library/Homebrew/test/support/helper/spec/shared_examples/formulae_exist.rb
index 8b39d54fc81ac..184c34b541a6e 100644
--- a/Library/Homebrew/test/support/helper/spec/shared_examples/formulae_exist.rb
+++ b/Library/Homebrew/test/support/helper/spec/shared_examples/formulae_exist.rb
@@ -2,7 +2,7 @@
 
 RSpec.shared_examples "formulae exist" do |array|
   array.each do |f|
-    it "#{f} formula exists" do
+    it "#{f} formula exists", :needs_homebrew_core do
       core_tap = Pathname("#{HOMEBREW_LIBRARY_PATH}/../Taps/homebrew/homebrew-core")
       formula_paths = core_tap.glob("Formula/**/#{f}.rb")
       alias_path = core_tap/"Aliases/#{f}"