diff --git a/Library/Homebrew/software_spec.rb b/Library/Homebrew/software_spec.rb
index 63e9e1b89778c..baf07262a3cf8 100644
--- a/Library/Homebrew/software_spec.rb
+++ b/Library/Homebrew/software_spec.rb
@@ -87,8 +87,7 @@ def owner=(owner)
     resources.each_value do |r|
       r.owner = self
       next if r.version
-
-      raise "#{full_name}: version missing for \"#{r.name}\" resource!" if version.nil?
+      next if version.nil?
 
       r.version(version.head? ? Version.new("HEAD") : version.dup)
     end