diff --git a/services/document-updater/test/unit/coffee/ProjectManager/flushAndDeleteProjectTests.coffee b/services/document-updater/test/unit/coffee/ProjectManager/flushAndDeleteProjectTests.coffee
index fc2ea998f6..74161ca4a2 100644
--- a/services/document-updater/test/unit/coffee/ProjectManager/flushAndDeleteProjectTests.coffee
+++ b/services/document-updater/test/unit/coffee/ProjectManager/flushAndDeleteProjectTests.coffee
@@ -10,6 +10,7 @@ describe "ProjectManager - flushAndDeleteProject", ->
 			"./RedisManager": @RedisManager = {}
 			"./DocumentManager": @DocumentManager = {}
 			"logger-sharelatex": @logger = { log: sinon.stub(), error: sinon.stub() }
+			"./HistoryManager": @HistoryManager = {}
 			"./Metrics": @Metrics =
 				Timer: class Timer
 					done: sinon.stub()
diff --git a/services/document-updater/test/unit/coffee/ProjectManager/flushProjectTests.coffee b/services/document-updater/test/unit/coffee/ProjectManager/flushProjectTests.coffee
index 301740c015..613b25ae4d 100644
--- a/services/document-updater/test/unit/coffee/ProjectManager/flushProjectTests.coffee
+++ b/services/document-updater/test/unit/coffee/ProjectManager/flushProjectTests.coffee
@@ -10,6 +10,7 @@ describe "ProjectManager - flushProject", ->
 			"./RedisManager": @RedisManager = {}
 			"./DocumentManager": @DocumentManager = {}
 			"logger-sharelatex": @logger = { log: sinon.stub(), error: sinon.stub() }
+			"./HistoryManager": @HistoryManager = {}
 			"./Metrics": @Metrics =
 				Timer: class Timer
 					done: sinon.stub()
diff --git a/services/document-updater/test/unit/coffee/ProjectManager/getProjectDocsTests.coffee b/services/document-updater/test/unit/coffee/ProjectManager/getProjectDocsTests.coffee
index 8e3bc2206d..41870f41ad 100644
--- a/services/document-updater/test/unit/coffee/ProjectManager/getProjectDocsTests.coffee
+++ b/services/document-updater/test/unit/coffee/ProjectManager/getProjectDocsTests.coffee
@@ -11,6 +11,7 @@ describe "ProjectManager - getProjectDocsAndFlushIfOld", ->
 			"./RedisManager": @RedisManager = {}
 			"./DocumentManager": @DocumentManager = {}
 			"logger-sharelatex": @logger = { log: sinon.stub(), error: sinon.stub() }
+			"./HistoryManager": @HistoryManager = {}
 			"./Metrics": @Metrics =
 				Timer: class Timer
 					done: sinon.stub()
diff --git a/services/document-updater/test/unit/coffee/ProjectManager/updateProjectTests.coffee b/services/document-updater/test/unit/coffee/ProjectManager/updateProjectTests.coffee
index 898479a8c7..5753b7f2f1 100644
--- a/services/document-updater/test/unit/coffee/ProjectManager/updateProjectTests.coffee
+++ b/services/document-updater/test/unit/coffee/ProjectManager/updateProjectTests.coffee
@@ -10,17 +10,21 @@ describe "ProjectManager", ->
 			"./RedisManager": @RedisManager = {}
 			"./DocumentManager": @DocumentManager = {}
 			"logger-sharelatex": @logger = { log: sinon.stub(), error: sinon.stub() }
+			"./HistoryManager": @HistoryManager = {}
 			"./Metrics": @Metrics =
 				Timer: class Timer
 					done: sinon.stub()
 
 		@project_id = "project-id-123"
 		@user_id = "user-id-123"
+		@HistoryManager.shouldFlushHistoryOps = sinon.stub().returns(false)
+		@HistoryManager.flushProjectChangesAsync = sinon.stub()
 		@callback = sinon.stub()
 
 	describe "updateProjectWithLocks", ->
 		describe "rename operations", ->
 			beforeEach ->
+
 				@firstDocUpdate =
 					id: 1
 					pathname: 'foo'
@@ -55,6 +59,11 @@ describe "ProjectManager", ->
 						.calledWith(@project_id, @firstFileUpdate.id, @user_id, @firstFileUpdate)
 						.should.equal true
 
+				it "should not flush the history", ->
+					@HistoryManager.flushProjectChangesAsync
+						.calledWith(@project_id)
+						.should.equal false
+
 				it "should call the callback", ->
 					@callback.called.should.equal true
 
@@ -76,6 +85,16 @@ describe "ProjectManager", ->
 				it "should call the callback with the error", ->
 					@callback.calledWith(@error).should.equal true
 
+			describe "with enough ops to flush", ->
+				beforeEach ->
+					@HistoryManager.shouldFlushHistoryOps = sinon.stub().returns(true)
+					@ProjectManager.updateProjectWithLocks @project_id, @user_id, @docUpdates, @fileUpdates, @callback
+
+				it "should flush the history", ->
+					@HistoryManager.flushProjectChangesAsync
+						.calledWith(@project_id)
+						.should.equal true
+
 		describe "add operations", ->
 			beforeEach ->
 				@firstDocUpdate =
@@ -108,6 +127,11 @@ describe "ProjectManager", ->
 						.calledWith(@project_id, 'file', @firstFileUpdate.id, @user_id, @firstFileUpdate)
 						.should.equal true
 
+				it "should not flush the history", ->
+					@HistoryManager.flushProjectChangesAsync
+						.calledWith(@project_id)
+						.should.equal false
+
 				it "should call the callback", ->
 					@callback.called.should.equal true
 
@@ -129,3 +153,13 @@ describe "ProjectManager", ->
 				it "should call the callback with the error", ->
 					@callback.calledWith(@error).should.equal true
 
+			describe "with enough ops to flush", ->
+				beforeEach ->
+					@HistoryManager.shouldFlushHistoryOps = sinon.stub().returns(true)
+					@ProjectManager.updateProjectWithLocks @project_id, @user_id, @docUpdates, @fileUpdates, @callback
+
+				it "should flush the history", ->
+					@HistoryManager.flushProjectChangesAsync
+						.calledWith(@project_id)
+						.should.equal true
+