diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 7bb14aa4c..b54e7b008 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -113,7 +113,7 @@ class ApplicationController < ActionController::Base
     klass.reload_stale_associations!(cached_keys_with_value.values) if klass.respond_to?(:reload_stale_associations!)
 
     unless uncached_ids.empty?
-      uncached = klass.where(id: uncached_ids).with_includes.map { |item| [item.id, item] }.to_h
+      uncached = klass.where(id: uncached_ids).with_includes.each_with_object({}) { |item, h| h[item.id] = item }
 
       uncached.each_value do |item|
         Rails.cache.write(item, item)
diff --git a/app/lib/entity_cache.rb b/app/lib/entity_cache.rb
index 2aa37389c..8fff544a0 100644
--- a/app/lib/entity_cache.rb
+++ b/app/lib/entity_cache.rb
@@ -21,7 +21,7 @@ class EntityCache
     end
 
     unless uncached_ids.empty?
-      uncached = CustomEmoji.where(shortcode: shortcodes, domain: domain, disabled: false).map { |item| [item.shortcode, item] }.to_h
+      uncached = CustomEmoji.where(shortcode: shortcodes, domain: domain, disabled: false).each_with_object({}) { |item, h| h[item.shortcode] = item }
       uncached.each_value { |item| Rails.cache.write(to_key(:emoji, item.shortcode, domain), item, expires_in: MAX_EXPIRATION) }
     end
 
diff --git a/app/lib/formatter.rb b/app/lib/formatter.rb
index d13884ec8..05fd9eeb1 100644
--- a/app/lib/formatter.rb
+++ b/app/lib/formatter.rb
@@ -128,9 +128,9 @@ class Formatter
     return html if emojis.empty?
 
     emoji_map = if animate
-                  emojis.map { |e| [e.shortcode, full_asset_url(e.image.url)] }.to_h
+                  emojis.each_with_object({}) { |e, h| h[e.shortcode] = full_asset_url(e.image.url) }
                 else
-                  emojis.map { |e| [e.shortcode, full_asset_url(e.image.url(:static))] }.to_h
+                  emojis.each_with_object({}) { |e, h| h[e.shortcode] = full_asset_url(e.image.url(:static)) }
                 end
 
     i                     = -1
diff --git a/app/lib/settings/scoped_settings.rb b/app/lib/settings/scoped_settings.rb
index 5ee30825d..3653ab114 100644
--- a/app/lib/settings/scoped_settings.rb
+++ b/app/lib/settings/scoped_settings.rb
@@ -31,7 +31,7 @@ module Settings
 
     def all_as_records
       vars = thing_scoped
-      records = vars.map { |r| [r.var, r] }.to_h
+      records = vars.each_with_object({}) { |r, h| h[r.var] = r }
 
       Setting.default_settings.each do |key, default_value|
         next if records.key?(key) || default_value.is_a?(Hash)
@@ -65,7 +65,7 @@ module Settings
 
     class << self
       def default_settings
-        defaulting = DEFAULTING_TO_UNSCOPED.map { |k| [k, Setting[k]] }.to_h
+        defaulting = DEFAULTING_TO_UNSCOPED.each_with_object({}) { |k, h| h[k] = Setting[k] }
         Setting.default_settings.merge!(defaulting)
       end
     end
diff --git a/app/models/concerns/account_interactions.rb b/app/models/concerns/account_interactions.rb
index f5f833446..ad2909d91 100644
--- a/app/models/concerns/account_interactions.rb
+++ b/app/models/concerns/account_interactions.rb
@@ -45,9 +45,9 @@ module AccountInteractions
     end
 
     def domain_blocking_map(target_account_ids, account_id)
-      accounts_map    = Account.where(id: target_account_ids).select('id, domain').map { |a| [a.id, a.domain] }.to_h
+      accounts_map    = Account.where(id: target_account_ids).select('id, domain').each_with_object({}) { |a, h| h[a.id] = a.domain }
       blocked_domains = domain_blocking_map_by_domain(accounts_map.values.compact, account_id)
-      accounts_map.map { |id, domain| [id, blocked_domains[domain]] }.to_h
+      accounts_map.reduce({}) { |h, (id, domain)| h.merge(id => blocked_domains[domain]) }
     end
 
     def domain_blocking_map_by_domain(target_domains, account_id)
diff --git a/app/models/notification.rb b/app/models/notification.rb
index 78b180301..4233532d0 100644
--- a/app/models/notification.rb
+++ b/app/models/notification.rb
@@ -75,7 +75,7 @@ class Notification < ApplicationRecord
 
       return if account_ids.empty?
 
-      accounts = Account.where(id: account_ids).map { |a| [a.id, a] }.to_h
+      accounts = Account.where(id: account_ids).each_with_object({}) { |a, h| h[a.id] = a }
 
       cached_items.each do |item|
         item.from_account = accounts[item.from_account_id]
diff --git a/app/models/setting.rb b/app/models/setting.rb
index 033d09fd5..a5878e96a 100644
--- a/app/models/setting.rb
+++ b/app/models/setting.rb
@@ -40,7 +40,7 @@ class Setting < RailsSettings::Base
 
     def all_as_records
       vars    = thing_scoped
-      records = vars.map { |r| [r.var, r] }.to_h
+      records = vars.each_with_object({}) { |r, h| h[r.var] = r }
 
       default_settings.each do |key, default_value|
         next if records.key?(key) || default_value.is_a?(Hash)
diff --git a/app/models/status.rb b/app/models/status.rb
index 11a75f876..680081724 100644
--- a/app/models/status.rb
+++ b/app/models/status.rb
@@ -321,19 +321,19 @@ class Status < ApplicationRecord
     end
 
     def favourites_map(status_ids, account_id)
-      Favourite.select('status_id').where(status_id: status_ids).where(account_id: account_id).map { |f| [f.status_id, true] }.to_h
+      Favourite.select('status_id').where(status_id: status_ids).where(account_id: account_id).each_with_object({}) { |f, h| h[f.status_id] = true }
     end
 
     def reblogs_map(status_ids, account_id)
-      select('reblog_of_id').where(reblog_of_id: status_ids).where(account_id: account_id).reorder(nil).map { |s| [s.reblog_of_id, true] }.to_h
+      select('reblog_of_id').where(reblog_of_id: status_ids).where(account_id: account_id).reorder(nil).each_with_object({}) { |s, h| h[s.reblog_of_id] = true }
     end
 
     def mutes_map(conversation_ids, account_id)
-      ConversationMute.select('conversation_id').where(conversation_id: conversation_ids).where(account_id: account_id).map { |m| [m.conversation_id, true] }.to_h
+      ConversationMute.select('conversation_id').where(conversation_id: conversation_ids).where(account_id: account_id).each_with_object({}) { |m, h| h[m.conversation_id] = true }
     end
 
     def pins_map(status_ids, account_id)
-      StatusPin.select('status_id').where(status_id: status_ids).where(account_id: account_id).map { |p| [p.status_id, true] }.to_h
+      StatusPin.select('status_id').where(status_id: status_ids).where(account_id: account_id).each_with_object({}) { |p, h| h[p.status_id] = true }
     end
 
     def reload_stale_associations!(cached_items)
@@ -348,7 +348,7 @@ class Status < ApplicationRecord
 
       return if account_ids.empty?
 
-      accounts = Account.where(id: account_ids).map { |a| [a.id, a] }.to_h
+      accounts = Account.where(id: account_ids).each_with_object({}) { |a, h| h[a.id] = a }
 
       cached_items.each do |item|
         item.account = accounts[item.account_id]
diff --git a/app/models/trending_tags.rb b/app/models/trending_tags.rb
index c559651c6..3a8be2164 100644
--- a/app/models/trending_tags.rb
+++ b/app/models/trending_tags.rb
@@ -18,7 +18,7 @@ class TrendingTags
     def get(limit)
       key     = "#{KEY}:#{Time.now.utc.beginning_of_day.to_i}"
       tag_ids = redis.zrevrange(key, 0, limit - 1).map(&:to_i)
-      tags    = Tag.where(id: tag_ids).to_a.map { |tag| [tag.id, tag] }.to_h
+      tags    = Tag.where(id: tag_ids).to_a.each_with_object({}) { |tag, h| h[tag.id] = tag }
       tag_ids.map { |tag_id| tags[tag_id] }.compact
     end
 
diff --git a/app/services/batched_remove_status_service.rb b/app/services/batched_remove_status_service.rb
index b8ab58938..75d756495 100644
--- a/app/services/batched_remove_status_service.rb
+++ b/app/services/batched_remove_status_service.rb
@@ -12,12 +12,12 @@ class BatchedRemoveStatusService < BaseService
   def call(statuses)
     statuses = Status.where(id: statuses.map(&:id)).includes(:account, :stream_entry).flat_map { |status| [status] + status.reblogs.includes(:account, :stream_entry).to_a }
 
-    @mentions = statuses.map { |s| [s.id, s.active_mentions.includes(:account).to_a] }.to_h
-    @tags     = statuses.map { |s| [s.id, s.tags.pluck(:name)] }.to_h
+    @mentions = statuses.each_with_object({}) { |s, h| h[s.id] = s.active_mentions.includes(:account).to_a }
+    @tags     = statuses.each_with_object({}) { |s, h| h[s.id] = s.tags.pluck(:name) }
 
     @stream_entry_batches  = []
     @salmon_batches        = []
-    @json_payloads         = statuses.map { |s| [s.id, Oj.dump(event: :delete, payload: s.id.to_s)] }.to_h
+    @json_payloads         = statuses.each_with_object({}) { |s, h| h[s.id] = Oj.dump(event: :delete, payload: s.id.to_s) }
     @activity_xml          = {}
 
     # Ensure that rendered XML reflects destroyed state
diff --git a/spec/models/notification_spec.rb b/spec/models/notification_spec.rb
index c781f2a29..be5545646 100644
--- a/spec/models/notification_spec.rb
+++ b/spec/models/notification_spec.rb
@@ -101,7 +101,7 @@ RSpec.describe Notification, type: :model do
       before do
         allow(accounts_with_ids).to receive(:[]).with(stale_account1.id).and_return(account1)
         allow(accounts_with_ids).to receive(:[]).with(stale_account2.id).and_return(account2)
-        allow(Account).to receive_message_chain(:where, :map, :to_h).and_return(accounts_with_ids)
+        allow(Account).to receive_message_chain(:where, :each_with_object).and_return(accounts_with_ids)
       end
 
       let(:cached_items) do