diff --git a/Library/Homebrew/tap_constants.rb b/Library/Homebrew/tap_constants.rb
index 3eb319747861e1693e26ef5d37405131dfd4700d..12de02f492213abf46055b33f2bc8a76e70ec2cc 100644
--- a/Library/Homebrew/tap_constants.rb
+++ b/Library/Homebrew/tap_constants.rb
@@ -1,5 +1,5 @@
 # match taps' formulae, e.g. someuser/sometap/someformula
-HOMEBREW_TAP_FORMULA_REGEX = %r{^([\w-]+)/([\w-]+)/([\w+-.]+)$}
+HOMEBREW_TAP_FORMULA_REGEX = %r{^([\w-]+)/([\w-]+)/([\w+-.@]+)$}
 # match taps' directory paths, e.g. HOMEBREW_LIBRARY/Taps/someuser/sometap
 HOMEBREW_TAP_DIR_REGEX = %r{#{Regexp.escape(HOMEBREW_LIBRARY.to_s)}/Taps/([\w-]+)/([\w-]+)}
 # match taps' formula paths, e.g. HOMEBREW_LIBRARY/Taps/someuser/sometap/someformula