diff --git a/db/fixtures/development/13_comments.rb b/db/fixtures/development/13_comments.rb
index f19beaefcb7a8f6f1f6b6f087bb417531415715f..519d91af0c11c387ee8f3953930eae3099a04ed2 100644
--- a/db/fixtures/development/13_comments.rb
+++ b/db/fixtures/development/13_comments.rb
@@ -1,7 +1,7 @@
 require './spec/support/sidekiq_middleware'
 
 Gitlab::Seeder.quiet do
-  Issue.find_each do |issue|
+  Gitlab::Seeder.parallel_each(Issue.preload(:project).all) do |issue|
     project = issue.project
 
     project.team.users.each do |user|
@@ -18,7 +18,7 @@
     end
   end
 
-  MergeRequest.find_each do |mr|
+  Gitlab::Seeder.parallel_each(MergeRequest.all) do |mr|
     project = mr.project
 
     project.team.users.each do |user|
diff --git a/lib/gitlab/seeder.rb b/lib/gitlab/seeder.rb
index e2c8c0ccdd011289ec39e8877861d0c45a41f765..8b1cc6785220775c3161b0f3a490dfbc9a10b950 100644
--- a/lib/gitlab/seeder.rb
+++ b/lib/gitlab/seeder.rb
@@ -45,6 +45,21 @@ module UserSeed
       end
     end
 
+    def self.parallel_each(array)
+      raise 'Nested Gitlab::Seeder.parallel_each calls are not allowed.' if @parallel
+
+      @parallel = true
+
+      # Closing gRPC channels before forking prevents segfaults when Ruby
+      # finalizes inherited gRPC objects in the child process.
+      # See https://gitlab.com/gitlab-org/gitlab/-/issues/480716#note_2787476778
+      Gitlab::GitalyClient.clear_stubs!
+
+      Parallel.each(array, in_processes: Parallel.processor_count) { |record| yield(record) }
+    ensure
+      @parallel = false
+    end
+
     def self.log_message(message)
       puts "#{Time.current}: #{message}"
     end