1 files changed, 3 insertions, 1 deletions
diff --git a/Library/Homebrew/tap.rb b/Library/Homebrew/tap.rb
index e77390ab1..a564b3170 100644
--- a/Library/Homebrew/tap.rb
+++ b/Library/Homebrew/tap.rb
@@ -25,7 +25,9 @@ class Tap
       repo = args[1]
     end
 
-    raise "Invalid tap name" unless user && repo
+    if [user, repo].any? { |part| part.nil? || part.include?("/") }
+      raise "Invalid tap name '#{args.join("/")}'"
+    end
 
     # we special case homebrew so users don't have to shift in a terminal
     user = "Homebrew" if user == "homebrew"