diff --git a/lib/mihari/enrichers/whois.rb b/lib/mihari/enrichers/whois.rb
index f00678ad..9ef59c39 100644
--- a/lib/mihari/enrichers/whois.rb
+++ b/lib/mihari/enrichers/whois.rb
@@ -16,7 +16,9 @@ class Whois < Base
       def call(artifact)
         return if artifact.domain.nil?
 
-        artifact.whois_record ||= memoized_lookup(PublicSuffix.domain(artifact.domain))
+        artifact.tap do |tapped|
+          tapped.whois_record ||= memoized_lookup(PublicSuffix.domain(artifact.domain))
+        end
       end
 
       private
diff --git a/lib/mihari/models/artifact.rb b/lib/mihari/models/artifact.rb
index 82fd642c..c3989756 100644
--- a/lib/mihari/models/artifact.rb
+++ b/lib/mihari/models/artifact.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "ostruct"
+
 module Mihari
   module Models
     #
@@ -158,10 +160,7 @@ class Artifact < ActiveRecord::Base
       # @return [Boolean] true if it is unique. Otherwise false.
       #
       def unique?(base_time: nil, artifact_ttl: nil)
-        artifact = self.class.joins(:alert).where(
-          data:,
-          alert: {rule_id:}
-        ).order(created_at: :desc).first
+        artifact = self.class.joins(:alert).where(data:, alert: {rule_id:}).order(created_at: :desc).first
         return true if artifact.nil?
 
         # check whether the artifact is decayed or not
@@ -179,7 +178,32 @@ def enrichable?
       end
 
       def enrich
-        callable_enrichers.each { |enricher| enricher.result self }
+        enrich_by_enrichers callable_enrichers
+      end
+
+      #
+      # @param [Array<Mihari::Enrichers::Base>] enrichers
+      # @param [Boolean] parallel
+      #
+      # @return [Mihari::Models::Artifact]
+      #
+      def enrich_by_enrichers(enrichers)
+        # NOTE: doing parallel with ActiveRecord objects is troublesome (e.g. connection issue, etc.)
+        #       so converting the object to an OpenStruct object
+        s = struct
+        results = Parallel.map(enrichers) { |enricher| enricher.result s }
+        enriched = results.compact.map { |result| result.value_or(nil) }.compact
+
+        self.dns_records = enriched.map(&:dns_records).flatten.compact
+        self.cpes = enriched.map(&:cpes).flatten.compact
+        self.ports = enriched.map(&:ports).flatten.compact
+        self.vulnerabilities = enriched.map(&:vulnerabilities).flatten.compact
+
+        self.autonomous_system = enriched.map(&:autonomous_system).compact.first
+        self.geolocation = enriched.map(&:geolocation).compact.first
+        self.whois_record = enriched.map(&:whois_record).compact.first
+
+        self
       end
 
       #
@@ -195,6 +219,18 @@ def domain
         end
       end
 
+      def struct
+        OpenStruct.new(attributes).tap do |s|
+          s.domain = domain
+          s.cpes ||= []
+          s.dns_records ||= []
+          s.ports ||= []
+          s.reverse_dns_names ||= []
+          s.vulnerabilities ||= []
+          s.tags ||= []
+        end
+      end
+
       class << self
         # @!method search_by_filter(filter)
         #   @param [Mihari::Structs::Filters::Search] filter
@@ -212,7 +248,7 @@ class << self
       #
       def callable_enrichers
         @callable_enrichers ||= Mihari.enrichers.map(&:new).select do |enricher|
-          enricher.callable?(self)
+          enricher.callable? self
         end
       end
 
diff --git a/lib/mihari/rule.rb b/lib/mihari/rule.rb
index db0b748a..647c7710 100644
--- a/lib/mihari/rule.rb
+++ b/lib/mihari/rule.rb
@@ -178,10 +178,7 @@ def unique_artifacts
     #
     def enriched_artifacts
       @enriched_artifacts ||= Parallel.map(unique_artifacts) do |artifact|
-        artifact.tap do |tapped|
-          # NOTE: To apply changes correctly, enrichers should be applied to an artifact serially
-          enrichers.each { |enricher| enricher.result(tapped) }
-        end
+        artifact.enrich_by_enrichers enrichers
       end
     end