diff --git a/CHANGELOG.md b/CHANGELOG.md
index c6358bd9d2..94600e90f3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 # Changelog
 
+* `#2449` Squash old migrations
+
 ## 4.0.0.pre6
 
 * New core version dependency.
diff --git a/db/migrate/20101111150110_adjust_cost_query_layout.rb b/db/migrate/20101111150110_adjust_cost_query_layout.rb
deleted file mode 100644
index 527517a4c2..0000000000
--- a/db/migrate/20101111150110_adjust_cost_query_layout.rb
+++ /dev/null
@@ -1,17 +0,0 @@
-class AdjustCostQueryLayout < ActiveRecord::Migration
-  def self.up
-    remove_column :cost_queries, :filters
-    remove_column :cost_queries, :group_by
-    remove_column :cost_queries, :granularity
-
-    add_column :cost_queries, :yamlized, :string, :null => true
-  end
-
-  def self.down
-    add_column :cost_queries, :filters, :text
-    add_column :cost_queries, :group_bys, :text
-    add_column :cost_queries, :granularity, :string
-
-    remove_column :cost_queries, :yamlized
-  end
-end
diff --git a/db/migrate/20101124150110_adjust_cost_query_layout_some_more.rb b/db/migrate/20101124150110_adjust_cost_query_layout_some_more.rb
deleted file mode 100644
index af4e869703..0000000000
--- a/db/migrate/20101124150110_adjust_cost_query_layout_some_more.rb
+++ /dev/null
@@ -1,11 +0,0 @@
-class AdjustCostQueryLayoutSomeMore < ActiveRecord::Migration
-  def self.up
-    remove_column :cost_queries, :display_cost_entries
-    remove_column :cost_queries, :display_time_entries
-  end
-
-  def self.down
-    add_column :cost_queries, :display_cost_entries, :boolean, :default => true
-    add_column :cost_queries, :display_time_entries, :boolean, :default => true
-  end
-end
diff --git a/db/migrate/20101202142038_change_cost_query_yaml_length.rb b/db/migrate/20101202142038_change_cost_query_yaml_length.rb
deleted file mode 100644
index 81a99e264a..0000000000
--- a/db/migrate/20101202142038_change_cost_query_yaml_length.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-class ChangeCostQueryYamlLength < ActiveRecord::Migration
-  def self.up
-    change_column :cost_queries, :yamlized, :string, :limit => 2000, :null => false
-  end
-
-  def self.down
-    change_column :cost_queries, :yamlized, :string, :length => 255, :null => false
-  end
-end
diff --git a/db/migrate/20101203110501_rename_yamlized_to_serialized.rb b/db/migrate/20101203110501_rename_yamlized_to_serialized.rb
deleted file mode 100644
index 3f5f9374f4..0000000000
--- a/db/migrate/20101203110501_rename_yamlized_to_serialized.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-class RenameYamlizedToSerialized < ActiveRecord::Migration
-  def self.up
-    rename_column :cost_queries, :yamlized, :serialized
-  end
-
-  def self.down
-    rename_column :cost_queries, :serialized, :yamlized
-  end
-end
diff --git a/db/migrate/20110215143010_add_timestamps_to_custom_fields.rb b/db/migrate/20110215143010_add_timestamps_to_custom_fields.rb
deleted file mode 100644
index f72bd9e85a..0000000000
--- a/db/migrate/20110215143010_add_timestamps_to_custom_fields.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-class AddTimestampsToCustomFields < ActiveRecord::Migration
-  def self.up
-    add_timestamps :custom_fields
-  end
-
-  def self.down
-    remove_timestamps :custom_fields
-  end
-end
diff --git a/db/migrate/20110215143061_aggregated_reporting_migrations.rb b/db/migrate/20110215143061_aggregated_reporting_migrations.rb
new file mode 100644
index 0000000000..931f033f20
--- /dev/null
+++ b/db/migrate/20110215143061_aggregated_reporting_migrations.rb
@@ -0,0 +1,38 @@
+require Rails.root.join("db","migrate","migration_utils","migration_squasher").to_s
+require 'open_project/plugins/migration_mapping'
+# This migration aggregates the migrations detailed in MIGRATION_FILES
+class AggregatedReportingMigrations < ActiveRecord::Migration
+
+  MIGRATION_FILES = <<-MIGRATIONS
+    20101111150110_adjust_cost_query_layout.rb
+    20101124150110_adjust_cost_query_layout_some_more.rb
+    20101202142038_change_cost_query_yaml_length.rb
+    20101203110501_rename_yamlized_to_serialized.rb
+    20110215143010_add_timestamps_to_custom_fields.rb
+  MIGRATIONS
+
+  OLD_PLUGIN_NAME = "redmine_reporting"
+
+  def up
+    migration_names = OpenProject::Plugins::MigrationMapping.migration_files_to_migration_names(MIGRATION_FILES, OLD_PLUGIN_NAME)
+    Migration::MigrationSquasher.squash(migration_names) do
+      create_table "cost_queries" do |t|
+        t.integer  "user_id",                                       :null => false
+        t.integer  "project_id"
+        t.string   "name",                                          :null => false
+        t.boolean  "is_public",                  :default => false, :null => false
+        t.datetime "created_on",                                    :null => false
+        t.datetime "updated_on",                                    :null => false
+        t.string   "serialized", :limit => 2000,                    :null => false
+      end
+
+      add_timestamps :custom_fields
+    end
+  end
+
+  def down
+    drop_table "cost_queries"
+    remove_timestamps :custom_fields
+  end
+end
+
diff --git a/lib/open_project/reporting/engine.rb b/lib/open_project/reporting/engine.rb
index 8de078b195..766b7f983d 100644
--- a/lib/open_project/reporting/engine.rb
+++ b/lib/open_project/reporting/engine.rb
@@ -34,6 +34,14 @@ module OpenProject::Reporting
       FactoryGirl.definition_file_paths << File.expand_path(self.root.to_s + '/spec/factories') if defined?(FactoryGirl)
     end
 
+    initializer :append_migrations do |app|
+      unless app.root.to_s.match root.to_s
+        config.paths["db/migrate"].expanded.each do |expanded_path|
+          app.config.paths["db/migrate"] << expanded_path
+        end
+      end
+    end
+
     config.to_prepare do
       require_dependency 'report/walker'
       require_dependency 'report/transformer'