diff --git a/spec/text-editor-spec.coffee b/spec/text-editor-spec.coffee
index 43265c58d..02d2e4a96 100644
--- a/spec/text-editor-spec.coffee
+++ b/spec/text-editor-spec.coffee
@@ -22,17 +22,6 @@ describe "TextEditor", ->
       atom.packages.activatePackage('language-javascript')
 
   describe "when the editor is deserialized", ->
-    it "returns undefined when the path cannot be read", ->
-      pathToOpen = path.join(temp.mkdirSync(), 'file.txt')
-      editor1 = null
-
-      waitsForPromise ->
-        atom.workspace.open(pathToOpen).then (o) -> editor1 = o
-
-      runs ->
-        fs.mkdirSync(pathToOpen)
-        expect(TextEditor.deserialize(editor1.serialize(), atom)).toBeUndefined()
-
     it "restores selections and folds based on markers in the buffer", ->
       editor.setSelectedBufferRange([[1, 2], [3, 4]])
       editor.addSelectionForBufferRange([[5, 6], [7, 5]], reversed: true)
diff --git a/spec/tokenized-buffer-spec.coffee b/spec/tokenized-buffer-spec.coffee
index 692e758a9..76314681c 100644
--- a/spec/tokenized-buffer-spec.coffee
+++ b/spec/tokenized-buffer-spec.coffee
@@ -24,6 +24,34 @@ describe "TokenizedBuffer", ->
     advanceClock() while tokenizedBuffer.firstInvalidRow()?
     changeHandler?.reset()
 
+  describe "serialization", ->
+    describe "when the underlying buffer has a path", ->
+      it "deserializes it searching among the buffers in the current project", ->
+        buffer = atom.project.bufferForPathSync('sample.js')
+        tokenizedBufferA = new TokenizedBuffer({
+          buffer, config: atom.config, grammarRegistry: atom.grammars, packageManager: atom.packages, assert: atom.assert
+        })
+        tokenizedBufferB = TokenizedBuffer.deserialize(
+          JSON.parse(JSON.stringify(tokenizedBufferA.serialize())),
+          atom
+        )
+
+        expect(tokenizedBufferB.buffer).toBe(tokenizedBufferA.buffer)
+
+    describe "when the underlying buffer has no path", ->
+      it "deserializes it searching among the buffers in the current project", ->
+        buffer = atom.project.bufferForPathSync(null)
+
+        tokenizedBufferA = new TokenizedBuffer({
+          buffer, config: atom.config, grammarRegistry: atom.grammars, packageManager: atom.packages, assert: atom.assert
+        })
+        tokenizedBufferB = TokenizedBuffer.deserialize(
+          JSON.parse(JSON.stringify(tokenizedBufferA.serialize())),
+          atom
+        )
+
+        expect(tokenizedBufferB.buffer).toBe(tokenizedBufferA.buffer)
+
   describe "when the buffer is destroyed", ->
     beforeEach ->
       buffer = atom.project.bufferForPathSync('sample.js')
diff --git a/spec/workspace-spec.coffee b/spec/workspace-spec.coffee
index e06a3e598..35585479b 100644
--- a/spec/workspace-spec.coffee
+++ b/spec/workspace-spec.coffee
@@ -43,6 +43,9 @@ describe "Workspace", ->
         pane3 = pane2.splitRight(copyActiveItem: true)
         pane4 = null
 
+        waitsForPromise ->
+          atom.workspace.open(null).then (editor) -> editor.setText("An untitled editor.")
+
         waitsForPromise ->
           atom.workspace.open('b').then (editor) ->
             pane2.activateItem(editor.copy())
@@ -65,15 +68,16 @@ describe "Workspace", ->
 
           simulateReload()
 
-          expect(atom.workspace.getTextEditors().length).toBe 4
-          [editor1, editor2, editor3, editor4] = atom.workspace.getTextEditors()
-
+          expect(atom.workspace.getTextEditors().length).toBe 5
+          [editor1, editor2, untitledEditor, editor3, editor4] = atom.workspace.getTextEditors()
           expect(editor1.getPath()).toBe atom.project.getDirectories()[0]?.resolve('b')
           expect(editor2.getPath()).toBe atom.project.getDirectories()[0]?.resolve('../sample.txt')
           expect(editor2.getCursorScreenPosition()).toEqual [0, 2]
           expect(editor3.getPath()).toBe atom.project.getDirectories()[0]?.resolve('b')
           expect(editor4.getPath()).toBe atom.project.getDirectories()[0]?.resolve('../sample.js')
           expect(editor4.getCursorScreenPosition()).toEqual [2, 4]
+          expect(untitledEditor.getPath()).toBeUndefined()
+          expect(untitledEditor.getText()).toBe("An untitled editor.")
 
           expect(atom.workspace.getActiveTextEditor().getPath()).toBe editor3.getPath()
           expect(document.title).toMatch ///^#{path.basename(editor3.getLongTitle())}\ \u2014\ #{atom.project.getPaths()[0]}///
diff --git a/src/project.coffee b/src/project.coffee
index bb9c8be80..d59c041cb 100644
--- a/src/project.coffee
+++ b/src/project.coffee
@@ -308,12 +308,20 @@ class Project extends Model
   findBufferForPath: (filePath) ->
     _.find @buffers, (buffer) -> buffer.getPath() is filePath
 
+  findBufferForId: (id) ->
+    _.find @buffers, (buffer) -> buffer.getId() is id
+
   # Only to be used in specs
   bufferForPathSync: (filePath) ->
     absoluteFilePath = @resolvePath(filePath)
     existingBuffer = @findBufferForPath(absoluteFilePath) if filePath
     existingBuffer ? @buildBufferSync(absoluteFilePath)
 
+  # Only to be used when deserializing
+  bufferForIdSync: (id) ->
+    existingBuffer = @findBufferForId(id) if id
+    existingBuffer ? @buildBufferSync()
+
   # Given a file path, this retrieves or creates a new {TextBuffer}.
   #
   # If the `filePath` already has a `buffer`, that value is used instead. Otherwise,
@@ -329,9 +337,6 @@ class Project extends Model
     else
       @buildBuffer(absoluteFilePath)
 
-  bufferForId: (id) ->
-    _.find @buffers, (buffer) -> buffer.id is id
-
   # Still needed when deserializing a tokenized buffer
   buildBufferSync: (absoluteFilePath) ->
     buffer = new TextBuffer({filePath: absoluteFilePath})
diff --git a/src/text-editor.coffee b/src/text-editor.coffee
index a151c9dba..1435aef19 100644
--- a/src/text-editor.coffee
+++ b/src/text-editor.coffee
@@ -677,7 +677,7 @@ class TextEditor extends Model
   # this editor.
   shouldPromptToSave: ({windowCloseRequested}={}) ->
     if windowCloseRequested
-      @isModified()
+      false
     else
       @isModified() and not @buffer.hasMultipleEditors()
 
diff --git a/src/tokenized-buffer.coffee b/src/tokenized-buffer.coffee
index 2df29a31c..cdafc2869 100644
--- a/src/tokenized-buffer.coffee
+++ b/src/tokenized-buffer.coffee
@@ -22,7 +22,11 @@ class TokenizedBuffer extends Model
   changeCount: 0
 
   @deserialize: (state, atomEnvironment) ->
-    state.buffer = atomEnvironment.project.bufferForPathSync(state.bufferPath)
+    if state.bufferId
+      state.buffer = atomEnvironment.project.bufferForIdSync(state.bufferId)
+    else
+      # TODO: remove this fallback after everyone transitions to the latest version.
+      state.buffer = atomEnvironment.project.bufferForPathSync(state.bufferPath)
     state.config = atomEnvironment.config
     state.grammarRegistry = atomEnvironment.grammars
     state.packageManager = atomEnvironment.packages
@@ -53,6 +57,7 @@ class TokenizedBuffer extends Model
   serialize: ->
     deserializer: 'TokenizedBuffer'
     bufferPath: @buffer.getPath()
+    bufferId: @buffer.getId()
     tabLength: @tabLength
     ignoreInvisibles: @ignoreInvisibles
     largeFileMode: @largeFileMode