diff --git a/lib/mihari/schemas/alert.rb b/lib/mihari/schemas/alert.rb
index 1084c140..2b3e43c2 100644
--- a/lib/mihari/schemas/alert.rb
+++ b/lib/mihari/schemas/alert.rb
@@ -3,9 +3,9 @@
 module Mihari
   module Schemas
     Alert = Dry::Schema.Params do
-      required(:rule_id).value(:string)
-      required(:artifacts).value(array[:string])
-      optional(:source).value(:string)
+      required(:rule_id).filled(:string)
+      required(:artifacts).array { filled(:string) }
+      optional(:source).filled(:string)
     end
 
     #
diff --git a/lib/mihari/schemas/analyzer.rb b/lib/mihari/schemas/analyzer.rb
index 407cbfb6..5851b44e 100644
--- a/lib/mihari/schemas/analyzer.rb
+++ b/lib/mihari/schemas/analyzer.rb
@@ -20,8 +20,8 @@ module Analyzers
         key = keys.first
         const_set(key.upcase, Dry::Schema.Params do
           required(:analyzer).value(Types::String.enum(*keys))
-          required(:query).value(:string)
-          optional(:api_key).value(:string)
+          required(:query).filled(:string)
+          optional(:api_key).filled(:string)
           optional(:options).hash(AnalyzerPaginationOptions)
         end)
       end
@@ -36,60 +36,60 @@ module Analyzers
         key = keys.first
         const_set(key.upcase, Dry::Schema.Params do
           required(:analyzer).value(Types::String.enum(*keys))
-          required(:query).value(:string)
-          optional(:api_key).value(:string)
+          required(:query).filled(:string)
+          optional(:api_key).filled(:string)
           optional(:options).hash(AnalyzerOptions)
         end)
       end
 
       DNSTwister = Dry::Schema.Params do
         required(:analyzer).value(Types::String.enum(*Mihari::Analyzers::DNSTwister.keys))
-        required(:query).value(:string)
+        required(:query).filled(:string)
         optional(:options).hash(AnalyzerOptions)
       end
 
       Censys = Dry::Schema.Params do
         required(:analyzer).value(Types::String.enum(*Mihari::Analyzers::Censys.keys))
-        required(:query).value(:string)
-        optional(:id).value(:string)
-        optional(:secret).value(:string)
+        required(:query).filled(:string)
+        optional(:id).filled(:string)
+        optional(:secret).filled(:string)
         optional(:options).hash(AnalyzerPaginationOptions)
       end
 
       CIRCL = Dry::Schema.Params do
         required(:analyzer).value(Types::String.enum(*Mihari::Analyzers::CIRCL.keys))
-        required(:query).value(:string)
-        optional(:username).value(:string)
-        optional(:password).value(:string)
+        required(:query).filled(:string)
+        optional(:username).filled(:string)
+        optional(:password).filled(:string)
         optional(:options).hash(AnalyzerOptions)
       end
 
       Fofa = Dry::Schema.Params do
         required(:analyzer).value(Types::String.enum(*Mihari::Analyzers::Fofa.keys))
-        required(:query).value(:string)
-        optional(:api_key).value(:string)
-        optional(:email).value(:string)
+        required(:query).filled(:string)
+        optional(:api_key).filled(:string)
+        optional(:email).filled(:string)
         optional(:options).hash(AnalyzerPaginationOptions)
       end
 
       PassiveTotal = Dry::Schema.Params do
         required(:analyzer).value(Types::String.enum(*Mihari::Analyzers::PassiveTotal.keys))
-        required(:query).value(:string)
-        optional(:username).value(:string)
-        optional(:api_key).value(:string)
+        required(:query).filled(:string)
+        optional(:username).filled(:string)
+        optional(:api_key).filled(:string)
         optional(:options).hash(AnalyzerOptions)
       end
 
       ZoomEye = Dry::Schema.Params do
         required(:analyzer).value(Types::String.enum(*Mihari::Analyzers::ZoomEye.keys))
-        required(:query).value(:string)
+        required(:query).filled(:string)
         required(:type).value(Types::String.enum("host", "web"))
         optional(:options).hash(AnalyzerPaginationOptions)
       end
 
       Crtsh = Dry::Schema.Params do
         required(:analyzer).value(Types::String.enum(*Mihari::Analyzers::Crtsh.keys))
-        required(:query).value(:string)
+        required(:query).filled(:string)
         optional(:exclude_expired).value(:bool).default(true)
         optional(:match).value(Types::String.enum("=", "ILIKE", "LIKE", "single", "any", "FTS")).default(nil)
         optional(:options).hash(AnalyzerOptions)
@@ -97,22 +97,22 @@ module Analyzers
 
       HunterHow = Dry::Schema.Params do
         required(:analyzer).value(Types::String.enum(*Mihari::Analyzers::HunterHow.keys))
-        required(:query).value(:string)
+        required(:query).filled(:string)
         required(:start_time).value(:date)
         required(:end_time).value(:date)
-        optional(:api_key).value(:string)
+        optional(:api_key).filled(:string)
         optional(:options).hash(AnalyzerPaginationOptions)
       end
 
       Feed = Dry::Schema.Params do
         required(:analyzer).value(Types::String.enum(*Mihari::Analyzers::Feed.keys))
-        required(:query).value(:string)
-        required(:selector).value(:string)
+        required(:query).filled(:string)
+        required(:selector).filled(:string)
         optional(:method).value(Types::HTTPRequestMethods).default("GET")
-        optional(:headers).value(:hash).default({})
-        optional(:params).value(:hash)
-        optional(:form).value(:hash)
-        optional(:json).value(:hash)
+        optional(:headers).filled(:hash)
+        optional(:params).filled(:hash)
+        optional(:form).filled(:hash)
+        optional(:json).filled(:hash)
         optional(:options).hash(AnalyzerOptions)
       end
     end
diff --git a/lib/mihari/schemas/emitter.rb b/lib/mihari/schemas/emitter.rb
index 5636733c..bf1b0d7f 100644
--- a/lib/mihari/schemas/emitter.rb
+++ b/lib/mihari/schemas/emitter.rb
@@ -15,31 +15,31 @@ module Emitters
 
       MISP = Dry::Schema.Params do
         required(:emitter).value(Types::String.enum(*Mihari::Emitters::MISP.keys))
-        optional(:url).value(:string)
-        optional(:api_key).value(:string)
+        optional(:url).filled(:string)
+        optional(:api_key).filled(:string)
         optional(:options).hash(Options)
       end
 
       TheHive = Dry::Schema.Params do
         required(:emitter).value(Types::String.enum(*Mihari::Emitters::TheHive.keys))
-        optional(:url).value(:string)
-        optional(:api_key).value(:string)
+        optional(:url).filled(:string)
+        optional(:api_key).filled(:string)
         optional(:options).hash(Options)
       end
 
       Slack = Dry::Schema.Params do
         required(:emitter).value(Types::String.enum(*Mihari::Emitters::Slack.keys))
-        optional(:webhook_url).value(:string)
-        optional(:channel).value(:string)
+        optional(:webhook_url).filled(:string)
+        optional(:channel).filled(:string)
         optional(:options).hash(Options)
       end
 
       Webhook = Dry::Schema.Params do
         required(:emitter).value(Types::String.enum(*Mihari::Emitters::Webhook.keys))
-        required(:url).value(:string)
+        required(:url).filled(:string)
         optional(:method).value(Types::HTTPRequestMethods).default("POST")
-        optional(:headers).value(:hash).default({})
-        optional(:template).value(:string)
+        optional(:headers).filled(:hash)
+        optional(:template).filled(:string)
         optional(:options).hash(Options)
       end
     end
diff --git a/lib/mihari/schemas/rule.rb b/lib/mihari/schemas/rule.rb
index 1fc912a9..795fced6 100644
--- a/lib/mihari/schemas/rule.rb
+++ b/lib/mihari/schemas/rule.rb
@@ -7,27 +7,27 @@
 module Mihari
   module Schemas
     Rule = Dry::Schema.Params do
-      required(:id).value(:string)
-      required(:title).value(:string)
-      required(:description).value(:string)
+      required(:id).filled(:string)
+      required(:title).filled(:string)
+      required(:description).filled(:string)
 
-      optional(:tags).value(array[:string]).default([])
+      optional(:author).filled(:string)
+      optional(:status).filled(:string)
 
-      optional(:author).value(:string)
-      optional(:references).value(array[:string])
-      optional(:related).value(array[:string])
-      optional(:status).value(:string)
+      optional(:tags).array { filled(:string) }.default([])
+      optional(:references).array { filled(:string) }
+      optional(:related).array { filled(:string) }
 
       optional(:created_on).value(:date)
       optional(:updated_on).value(:date)
 
       required(:queries).value(:array).each { Analyzer } # rubocop:disable Lint/Void
-
       optional(:emitters).value(:array).each { Emitter }.default(DEFAULT_EMITTERS) # rubocop:disable Lint/Void
       optional(:enrichers).value(:array).each { Enricher }.default(DEFAULT_ENRICHERS) # rubocop:disable Lint/Void
 
-      optional(:data_types).value(array[Types::DataTypes]).default(Mihari::Types::DataTypes.values)
-      optional(:falsepositives).value(array[:string]).default([])
+      optional(:data_types).filled(array[Types::DataTypes]).default(Mihari::Types::DataTypes.values)
+
+      optional(:falsepositives).array { filled(:string) }.default([])
 
       optional(:artifact_ttl).value(:integer)
     end
@@ -42,7 +42,7 @@ class RuleContract < Dry::Validation::Contract
 
       rule(:falsepositives) do
         value.each do |v|
-          key.failure("#{v} is not a valid format.") unless valid_falsepositive?(v)
+          key.failure("#{v} is not a valid format") unless valid_falsepositive?(v)
         end
       end