diff --git a/spec/workspace-spec.coffee b/spec/workspace-spec.coffee
index dac2849c0..0b32ff31f 100644
--- a/spec/workspace-spec.coffee
+++ b/spec/workspace-spec.coffee
@@ -426,6 +426,35 @@ describe "Workspace", ->
       workspace.decreaseFontSize()
       expect(atom.config.get('editor.fontSize')).toBe 1
 
+  describe "::resetFontSize()", ->
+    it "resets the font size to the window's starting font size", ->
+      originalFontSize = atom.config.get('editor.fontSize')
+
+      workspace.increaseFontSize()
+      expect(atom.config.get('editor.fontSize')).toBe originalFontSize + 1
+      workspace.resetFontSize()
+      expect(atom.config.get('editor.fontSize')).toBe originalFontSize
+      workspace.decreaseFontSize()
+      expect(atom.config.get('editor.fontSize')).toBe originalFontSize - 1
+      workspace.resetFontSize()
+      expect(atom.config.get('editor.fontSize')).toBe originalFontSize
+
+    it "does nothing if the font size has not been changed", ->
+      originalFontSize = atom.config.get('editor.fontSize')
+
+      workspace.resetFontSize()
+      expect(atom.config.get('editor.fontSize')).toBe originalFontSize
+
+    it "resets the font size when the editor's font size changes", ->
+      originalFontSize = atom.config.get('editor.fontSize')
+
+      atom.config.set('editor.fontSize', originalFontSize + 1)
+      workspace.resetFontSize()
+      expect(atom.config.get('editor.fontSize')).toBe originalFontSize
+      atom.config.set('editor.fontSize', originalFontSize - 1)
+      workspace.resetFontSize()
+      expect(atom.config.get('editor.fontSize')).toBe originalFontSize
+
   describe "::openLicense()", ->
     it "opens the license as plain-text in a buffer", ->
       waitsForPromise -> workspace.openLicense()
diff --git a/src/workspace.coffee b/src/workspace.coffee
index 50c4117fb..0e6fb7e40 100644
--- a/src/workspace.coffee
+++ b/src/workspace.coffee
@@ -75,6 +75,8 @@ class Workspace extends Model
     atom.views.addViewProvider Panel, (model) ->
       new PanelElement().initialize(model)
 
+    @subscribeToFontSize()
+
   # Called by the Serializable mixin during deserialization
   deserializeParams: (params) ->
     for packageName in params.packagesWithActiveGrammars ? []
@@ -619,9 +621,14 @@ class Workspace extends Model
     fontSize = atom.config.get("editor.fontSize")
     atom.config.set("editor.fontSize", fontSize - 1) if fontSize > 1
 
-  # Restore to a default editor font size.
+  # Restore to the window's original editor font size.
   resetFontSize: ->
-    atom.config.unset("editor.fontSize")
+    if @originalFontSize
+      atom.config.set("editor.fontSize", @originalFontSize)
+
+  subscribeToFontSize: ->
+    atom.config.onDidChange 'editor.fontSize', ({oldValue}) =>
+      @originalFontSize ?= oldValue
 
   # Removes the item's uri from the list of potential items to reopen.
   itemOpened: (item) ->