2 files changed, 9 insertions, 0 deletions
diff --git a/activeresource/lib/active_resource/base.rb b/activeresource/lib/active_resource/base.rb
index d31db9f0ba..80af7e7adf 100644
--- a/activeresource/lib/active_resource/base.rb
+++ b/activeresource/lib/active_resource/base.rb
@@ -621,6 +621,12 @@ module ActiveResource
       #   # => /posts/5/comments/1.xml?active=1
       #
       def element_path(id, prefix_options = {}, query_options = nil)
+
+        p_options = HashWithIndifferentAccess.new(prefix_options)
+        prefix_parameters.each do |p|
+          raise MissingPrefixParam if p_options[p].blank?
+        end
+
         prefix_options, query_options = split_options(prefix_options) if query_options.nil?
         "#{prefix(prefix_options)}#{collection_name}/#{URI.escape id.to_s}.#{format.extension}#{query_string(query_options)}"
       end
diff --git a/activeresource/lib/active_resource/exceptions.rb b/activeresource/lib/active_resource/exceptions.rb
index 0f4549fd73..6b953b28ad 100644
--- a/activeresource/lib/active_resource/exceptions.rb
+++ b/activeresource/lib/active_resource/exceptions.rb
@@ -36,6 +36,9 @@ module ActiveResource
     def to_s; response['Location'] ? "#{super} => #{response['Location']}" : super; end
   end
 
+  # Raised when ...
+  class MissingPrefixParam < ArgumentError; end # :nodoc:
+
   # 4xx Client Error
   class ClientError < ConnectionError; end # :nodoc: