diff --git a/Library/Homebrew/dev-cmd/create.rb b/Library/Homebrew/dev-cmd/create.rb
index 8b7ebff471..bd903fff35 100644
--- a/Library/Homebrew/dev-cmd/create.rb
+++ b/Library/Homebrew/dev-cmd/create.rb
@@ -176,10 +176,11 @@ module Homebrew
       print "Formula name [#{stem}]: "
       fc.name = __gets || stem
     end
-    raise TapUnavailableError, fc.tap.name unless fc.tap.installed?
 
     fc.url = args.named.first
 
+    fc.verify
+
     # Check for disallowed formula, or names that shadow aliases,
     # unless --force is specified.
     unless args.force?
diff --git a/Library/Homebrew/formula_creator.rb b/Library/Homebrew/formula_creator.rb
index 604ac6b686..02d26fa30f 100644
--- a/Library/Homebrew/formula_creator.rb
+++ b/Library/Homebrew/formula_creator.rb
@@ -9,7 +9,6 @@ module Homebrew
   #
   # @api private
   class FormulaCreator
-    attr_reader :tap
     attr_accessor :name
 
     sig {
@@ -26,6 +25,11 @@ module Homebrew
       @head = head
     end
 
+    sig { void }
+    def verify
+      raise TapUnavailableError, @tap.name unless @tap.installed?
+    end
+
     def url=(url)
       @url = url
       path = Pathname.new(url)