diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index a9bccf4549fd0529c2bd652096523b2a0a38441a..3095372a2f4228e64e01ef37f36e1ca1ed873c1a 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -637,6 +637,8 @@ class FormulaAuditor
 
     stable = formula.stable
     case stable && stable.url
+    when /[\d\._-](alpha|beta|rc\d)/
+      problem "Stable version URLs should not contain #{$1}"
     when %r{download\.gnome\.org/sources}, %r{ftp\.gnome\.org/pub/GNOME/sources}i
       version = Version.parse(stable.url)
       if version >= Version.create("1.0")