diff --git a/lib/diaspora_federation/validators/rules/birthday.rb b/lib/diaspora_federation/validators/rules/birthday.rb
index 3562922..89f97fe 100644
--- a/lib/diaspora_federation/validators/rules/birthday.rb
+++ b/lib/diaspora_federation/validators/rules/birthday.rb
@@ -3,13 +3,6 @@ require "date"
 module Validation
   module Rule
     class Birthday
-      attr_reader :params
-
-      # no parameters
-      def initialize
-        @params = {}
-      end
-
       def error_key
         :birthday
       end
@@ -25,6 +18,11 @@ module Validation
 
         false
       end
+
+      # This rule has no params
+      def params
+        {}
+      end
     end
   end
 end
diff --git a/lib/diaspora_federation/validators/rules/boolean.rb b/lib/diaspora_federation/validators/rules/boolean.rb
index f4498df..5ad166c 100644
--- a/lib/diaspora_federation/validators/rules/boolean.rb
+++ b/lib/diaspora_federation/validators/rules/boolean.rb
@@ -1,13 +1,6 @@
 module Validation
   module Rule
     class Boolean
-      attr_reader :params
-
-      # no parameters
-      def initialize
-        @params = {}
-      end
-
       def error_key
         :numeric
       end
@@ -25,6 +18,11 @@ module Validation
           false
         end
       end
+
+      # This rule has no params
+      def params
+        {}
+      end
     end
   end
 end
diff --git a/lib/diaspora_federation/validators/rules/guid.rb b/lib/diaspora_federation/validators/rules/guid.rb
index 7aca5d8..f559fc6 100644
--- a/lib/diaspora_federation/validators/rules/guid.rb
+++ b/lib/diaspora_federation/validators/rules/guid.rb
@@ -1,13 +1,6 @@
 module Validation
   module Rule
     class Guid
-      attr_reader :params
-
-      # no parameters
-      def initialize
-        @params = {}
-      end
-
       def error_key
         :guid
       end
@@ -15,6 +8,11 @@ module Validation
       def valid_value?(value)
         value.is_a?(String) && value.downcase =~ /\A[0-9a-z\-_@.:]{16,}\z/
       end
+
+      # This rule has no params
+      def params
+        {}
+      end
     end
   end
 end
diff --git a/lib/diaspora_federation/validators/rules/not_nil.rb b/lib/diaspora_federation/validators/rules/not_nil.rb
index 834384f..d3866ae 100644
--- a/lib/diaspora_federation/validators/rules/not_nil.rb
+++ b/lib/diaspora_federation/validators/rules/not_nil.rb
@@ -1,13 +1,6 @@
 module Validation
   module Rule
     class NotNil
-      attr_reader :params
-
-      # no parameters
-      def initialize
-        @params = {}
-      end
-
       def error_key
         :not_nil
       end
@@ -15,6 +8,11 @@ module Validation
       def valid_value?(value)
         !value.nil?
       end
+
+      # This rule has no params
+      def params
+        {}
+      end
     end
   end
 end
diff --git a/lib/diaspora_federation/validators/rules/public_key.rb b/lib/diaspora_federation/validators/rules/public_key.rb
index cc35e07..e7681ff 100644
--- a/lib/diaspora_federation/validators/rules/public_key.rb
+++ b/lib/diaspora_federation/validators/rules/public_key.rb
@@ -1,13 +1,6 @@
 module Validation
   module Rule
     class PublicKey
-      attr_reader :params
-
-      # no parameters
-      def initialize
-        @params = {}
-      end
-
       def error_key
         :public_key
       end
@@ -19,6 +12,11 @@ module Validation
         (value.strip.start_with?("-----BEGIN RSA PUBLIC KEY-----") &&
           value.strip.end_with?("-----END RSA PUBLIC KEY-----"))
       end
+
+      # This rule has no params
+      def params
+        {}
+      end
     end
   end
 end
diff --git a/lib/diaspora_federation/validators/rules/tag_count.rb b/lib/diaspora_federation/validators/rules/tag_count.rb
index 8f48082..e46fd7c 100644
--- a/lib/diaspora_federation/validators/rules/tag_count.rb
+++ b/lib/diaspora_federation/validators/rules/tag_count.rb
@@ -9,7 +9,7 @@ module Validation
       # @option params [Fixnum] :maximum maximum allowed tag count
       def initialize(params)
         unless params.include?(:maximum) && params[:maximum].is_a?(Fixnum)
-          raise "A number has to be specified for :maximum"
+          raise ArgumentError, "A number has to be specified for :maximum"
         end
 
         @params = params
diff --git a/spec/lib/diaspora_federation/validators/person_validator_spec.rb b/spec/lib/diaspora_federation/validators/person_validator_spec.rb
index f954d36..b4d462b 100644
--- a/spec/lib/diaspora_federation/validators/person_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/person_validator_spec.rb
@@ -20,6 +20,34 @@ module DiasporaFederation
       let(:property) { :guid }
     end
 
+    context "#url" do
+      it "fails for url with special chars" do
+        instance = OpenStruct.new(FactoryGirl.attributes_for(:person_entity, url: "https://asdf$%.com"))
+        validator = Validators::PersonValidator.new(instance)
+
+        expect(validator).not_to be_valid
+        expect(validator.errors).to include(:url)
+      end
+
+      it "fails for url without scheme" do
+        instance = OpenStruct.new(FactoryGirl.attributes_for(:person_entity, url: "example.com"))
+        validator = Validators::PersonValidator.new(instance)
+
+        expect(validator).not_to be_valid
+        expect(validator.errors).to include(:url)
+      end
+    end
+
+    context "#profile" do
+      it "fails if profile is nil" do
+        instance = OpenStruct.new(FactoryGirl.attributes_for(:person_entity, profile: nil))
+        validator = Validators::PersonValidator.new(instance)
+
+        expect(validator).not_to be_valid
+        expect(validator.errors).to include(:profile)
+      end
+    end
+
     context "#exported_key" do
       it "fails for malformed rsa key" do
         instance = OpenStruct.new(FactoryGirl.attributes_for(:person_entity, exported_key: "ASDF"))
diff --git a/spec/lib/diaspora_federation/validators/profile_validator_spec.rb b/spec/lib/diaspora_federation/validators/profile_validator_spec.rb
index ef11474..2339eee 100644
--- a/spec/lib/diaspora_federation/validators/profile_validator_spec.rb
+++ b/spec/lib/diaspora_federation/validators/profile_validator_spec.rb
@@ -19,6 +19,13 @@ module DiasporaFederation
 
     %i(first_name last_name).each do |prop|
       describe "##{prop}" do
+        it "allowed to be nil" do
+          validator = Validators::ProfileValidator.new(profile_stub(prop => nil))
+
+          expect(validator).to be_valid
+          expect(validator.errors).to be_empty
+        end
+
         it "allowed to contain special chars" do
           validator = Validators::ProfileValidator.new(profile_stub(prop => "cool name ©"))
 
diff --git a/spec/lib/diaspora_federation/validators/rules/not_nil_spec.rb b/spec/lib/diaspora_federation/validators/rules/not_nil_spec.rb
new file mode 100644
index 0000000..67d5646
--- /dev/null
+++ b/spec/lib/diaspora_federation/validators/rules/not_nil_spec.rb
@@ -0,0 +1,34 @@
+describe Validation::Rule::NotNil do
+  it "will not accept parameters" do
+    validator = Validation::Validator.new({})
+    expect {
+      validator.rule(:not_nil, not_nil: {param: true})
+    }.to raise_error ArgumentError
+  end
+
+  context "validation" do
+    it "validates a string " do
+      validator = Validation::Validator.new(OpenStruct.new(not_nil: "abcd"))
+      validator.rule(:not_nil, :not_nil)
+
+      expect(validator).to be_valid
+      expect(validator.errors).to be_empty
+    end
+
+    it "validates a object " do
+      validator = Validation::Validator.new(OpenStruct.new(not_nil: Object.new))
+      validator.rule(:not_nil, :not_nil)
+
+      expect(validator).to be_valid
+      expect(validator.errors).to be_empty
+    end
+
+    it "fails if it is nil" do
+      validator = Validation::Validator.new(OpenStruct.new(not_nil: nil))
+      validator.rule(:not_nil, :not_nil)
+
+      expect(validator).not_to be_valid
+      expect(validator.errors).to include(:not_nil)
+    end
+  end
+end
diff --git a/spec/lib/diaspora_federation/validators/rules/tag_count_spec.rb b/spec/lib/diaspora_federation/validators/rules/tag_count_spec.rb
index 32c1aa5..c301b41 100644
--- a/spec/lib/diaspora_federation/validators/rules/tag_count_spec.rb
+++ b/spec/lib/diaspora_federation/validators/rules/tag_count_spec.rb
@@ -6,6 +6,15 @@ describe Validation::Rule::TagCount do
     }.to raise_error ArgumentError
   end
 
+  it "requires a integer as parameter" do
+    validator = Validation::Validator.new({})
+    [nil, "", 5.5].each do |val|
+      expect {
+        validator.rule(:tags, tag_count: {maximum: val})
+      }.to raise_error ArgumentError, "A number has to be specified for :maximum"
+    end
+  end
+
   context "validation" do
     let(:tag_str) { "#i #love #tags" }