diff --git a/lib/diaspora_federation/validators/rules/diaspora_id.rb b/lib/diaspora_federation/validators/rules/diaspora_id.rb
index 001face..944a9b0 100644
--- a/lib/diaspora_federation/validators/rules/diaspora_id.rb
+++ b/lib/diaspora_federation/validators/rules/diaspora_id.rb
@@ -5,23 +5,25 @@ module Validation
     # A simple rule to validate the base structure of diaspora* IDs.
     class DiasporaId
       # The Regex for a valid diaspora* ID
-      DIASPORA_ID = begin
+      DIASPORA_ID_REGEX = begin
         letter         = "a-zA-Z"
         digit          = "0-9"
         hexadecimal    = "[a-fA-F#{digit}]"
         username       = "[#{letter}#{digit}\\-\\_\\.]+"
         hostname_part  = "[#{letter}#{digit}\\-]"
-        hostname       = "#{hostname_part}+([.]#{hostname_part}*)*"
+        hostname       = "#{hostname_part}+(?:[.]#{hostname_part}*)*"
         ipv4           = "(?:[#{digit}]{1,3}\\.){3}[#{digit}]{1,3}"
         ipv6           = "\\[(?:#{hexadecimal}{0,4}:){0,7}#{hexadecimal}{1,4}\\]"
         ip_addr        = "(?:#{ipv4}|#{ipv6})"
         domain         = "(?:#{hostname}|#{ip_addr})"
-        port           = "(:[#{digit}]+)?"
-        addr_spec      = "(#{username}\\@#{domain}#{port})?"
+        port           = "(?::[#{digit}]+)?"
 
-        /\A#{addr_spec}\z/u
+        "#{username}\\@#{domain}#{port}"
       end
 
+      # The Regex for validating a full diaspora* ID
+      DIASPORA_ID = /\A#{DIASPORA_ID_REGEX}\z/u
+
       # The error key for this rule
       # @return [Symbol] error key
       def error_key
@@ -30,7 +32,7 @@ module Validation
 
       # Determines if value is a valid diaspora* ID
       def valid_value?(value)
-        value.nil? || !DIASPORA_ID.match(value).nil?
+        value.is_a?(String) && value =~ DIASPORA_ID
       end
 
       # This rule has no params.
diff --git a/spec/lib/diaspora_federation/validators/rules/diaspora_id_spec.rb b/spec/lib/diaspora_federation/validators/rules/diaspora_id_spec.rb
index 0e9006a..178b190 100644
--- a/spec/lib/diaspora_federation/validators/rules/diaspora_id_spec.rb
+++ b/spec/lib/diaspora_federation/validators/rules/diaspora_id_spec.rb
@@ -83,13 +83,13 @@ describe Validation::Rule::DiasporaId do
       expect(validator.errors).to include(:diaspora_id)
     end
 
-    it "allows nil and empty" do
+    it "fails for nil and empty" do
       [nil, ""].each do |val|
         validator = Validation::Validator.new(OpenStruct.new(diaspora_id: val))
         validator.rule(:diaspora_id, :diaspora_id)
 
-        expect(validator).to be_valid
-        expect(validator.errors).to be_empty
+        expect(validator).not_to be_valid
+        expect(validator.errors).to include(:diaspora_id)
       end
     end
   end