diff --git a/lib/gitlab/gpg/commit.rb b/lib/gitlab/gpg/commit.rb
index ab7de14b07a..a03aeb9c293 100644
--- a/lib/gitlab/gpg/commit.rb
+++ b/lib/gitlab/gpg/commit.rb
@@ -3,17 +3,6 @@
 module Gitlab
   module Gpg
     class Commit < Gitlab::SignedCommit
-      def signature
-        super
-
-        return @signature if @signature
-
-        cached_signature = lazy_signature&.itself
-        return @signature = cached_signature if cached_signature.present?
-
-        @signature = create_cached_signature!
-      end
-
       def update_signature!(cached_signature)
         using_keychain do |gpg_key|
           cached_signature.update!(attributes(gpg_key))
@@ -23,12 +12,8 @@ module Gitlab
 
       private
 
-      def lazy_signature
-        BatchLoader.for(@commit.sha).batch do |shas, loader|
-          CommitSignatures::GpgSignature.by_commit_sha(shas).each do |signature|
-            loader.call(signature.commit_sha, signature)
-          end
-        end
+      def signature_class
+        CommitSignatures::GpgSignature
       end
 
       def using_keychain
diff --git a/lib/gitlab/signed_commit.rb b/lib/gitlab/signed_commit.rb
index 7a154978938..410e71f51a1 100644
--- a/lib/gitlab/signed_commit.rb
+++ b/lib/gitlab/signed_commit.rb
@@ -18,7 +18,18 @@ module Gitlab
     end
 
     def signature
-      return unless @commit.has_signature?
+      return @signature if @signature
+
+      cached_signature = lazy_signature&.itself
+
+      return @signature = cached_signature if cached_signature.present?
+
+      @signature = create_cached_signature!
+    end
+
+    def update_signature!(cached_signature)
+      cached_signature.update!(attributes)
+      @signature = cached_signature
     end
 
     def signature_text
@@ -32,5 +43,27 @@ module Gitlab
         @signature_data.itself ? @signature_data[1] : nil
       end
     end
+
+    private
+
+    def signature_class
+      raise NotImplementedError, '`signature_class` must be implmented by subclass`'
+    end
+
+    def lazy_signature
+      BatchLoader.for(@commit.sha).batch do |shas, loader|
+        signature_class.by_commit_sha(shas).each do |signature|
+          loader.call(signature.commit_sha, signature)
+        end
+      end
+    end
+
+    def create_cached_signature!
+      return if attributes.nil?
+
+      return signature_class.new(attributes) if Gitlab::Database.read_only?
+
+      signature_class.safe_create!(attributes)
+    end
   end
 end
diff --git a/lib/gitlab/x509/commit.rb b/lib/gitlab/x509/commit.rb
index c7f4b7cbdf5..3636e776a44 100644
--- a/lib/gitlab/x509/commit.rb
+++ b/lib/gitlab/x509/commit.rb
@@ -5,30 +5,10 @@ require 'digest'
 module Gitlab
   module X509
     class Commit < Gitlab::SignedCommit
-      def signature
-        super
-
-        return @signature if @signature
-
-        cached_signature = lazy_signature&.itself
-        return @signature = cached_signature if cached_signature.present?
-
-        @signature = create_cached_signature!
-      end
-
-      def update_signature!(cached_signature)
-        cached_signature.update!(attributes)
-        @signature = cached_signature
-      end
-
       private
 
-      def lazy_signature
-        BatchLoader.for(@commit.sha).batch do |shas, loader|
-          CommitSignatures::X509CommitSignature.by_commit_sha(shas).each do |signature|
-            loader.call(signature.commit_sha, signature)
-          end
-        end
+      def signature_class
+        CommitSignatures::X509CommitSignature
       end
 
       def attributes
@@ -45,14 +25,6 @@ module Gitlab
           verification_status: signature.verification_status
         }
       end
-
-      def create_cached_signature!
-        return if attributes.nil?
-
-        return CommitSignatures::X509CommitSignature.new(attributes) if Gitlab::Database.read_only?
-
-        CommitSignatures::X509CommitSignature.safe_create!(attributes)
-      end
     end
   end
 end