diff --git a/spec/display-buffer-spec.coffee b/spec/display-buffer-spec.coffee
index 51a6d8429..a75f7a91e 100644
--- a/spec/display-buffer-spec.coffee
+++ b/spec/display-buffer-spec.coffee
@@ -1040,29 +1040,36 @@ describe "DisplayBuffer", ->
         expect(start.left).toBe (4 * 10) + (6 * 11)
 
   describe "decorations", ->
-    it "can add decorations associated with markers and remove them", ->
-      decoration = {type: 'gutter', class: 'one'}
+    [marker, decoration, decorationParams] = []
+    beforeEach ->
       marker = displayBuffer.markBufferRange([[2, 13], [3, 15]])
+      decorationParams = {type: 'gutter', class: 'one'}
+      decoration = displayBuffer.decorateMarker(marker, decorationParams)
 
-      decorationObject = displayBuffer.decorateMarker(marker, decoration)
-      expect(decorationObject).toBeDefined()
-      expect(decorationObject.getParams()).toBe decoration
-      expect(displayBuffer.decorationForId(decoration.id)).toBe decorationObject
-      expect(displayBuffer.decorationsForScreenRowRange(2, 3)[marker.id][0]).toBe decorationObject
+    it "can add decorations associated with markers and remove them", ->
+      expect(decoration).toBeDefined()
+      expect(decoration.getParams()).toBe decoration
+      expect(displayBuffer.decorationForId(decoration.id)).toBe decoration
+      expect(displayBuffer.decorationsForScreenRowRange(2, 3)[marker.id][0]).toBe decoration
 
-      decorationObject.destroy()
+      decoration.destroy()
       expect(displayBuffer.decorationsForScreenRowRange(2, 3)[marker.id]).not.toBeDefined()
       expect(displayBuffer.decorationForId(decoration.id)).not.toBeDefined()
 
     it "will not fail if the decoration is removed twice", ->
-      decoration = {type: 'gutter', class: 'one'}
-      marker = displayBuffer.markBufferRange([[2, 13], [3, 15]])
-      decorationObject = displayBuffer.decorateMarker(marker, decoration)
-
-      decorationObject.destroy()
-      decorationObject.destroy()
+      decoration.destroy()
+      decoration.destroy()
       expect(displayBuffer.decorationForId(decoration.id)).not.toBeDefined()
 
+    describe "when a decoration is updated via Decoration::update()", ->
+      it "emits an 'updated' event containing the new and old params", ->
+        decoration.on 'updated', updatedSpy = jasmine.createSpy()
+        decoration.update type: 'gutter', class: 'two'
+
+        {oldParams, newParams} = updatedSpy.mostRecentCall.args[0]
+        expect(oldParams).toEqual decorationParams
+        expect(newParams).toEqual type: 'gutter', class: 'two', id: decoration.id
+
   describe "::setScrollTop", ->
     beforeEach ->
       displayBuffer.manageScrollPosition = true
diff --git a/spec/editor-component-spec.coffee b/spec/editor-component-spec.coffee
index 6858af29d..626f92079 100644
--- a/spec/editor-component-spec.coffee
+++ b/spec/editor-component-spec.coffee
@@ -973,7 +973,7 @@ describe "EditorComponent", ->
       regions = node.querySelectorAll('.test-highlight .region')
       expect(regions.length).toBe 2
 
-    describe "flashing a decoration via the Decoration::flash()", ->
+    describe "when flashing a decoration via Decoration::flash()", ->
       highlightNode = null
       beforeEach ->
         highlightNode = node.querySelector('.test-highlight')
@@ -1029,6 +1029,16 @@ describe "EditorComponent", ->
         regionStyle = node.querySelector('.test-highlight .region').style
         expect(parseInt(regionStyle.top)).toBe 5 * lineHeightInPixels
 
+    describe "when a decoration is updated via Decoration::update", ->
+      it "renders the decoration's new params", ->
+        expect(node.querySelector('.test-highlight')).toBeTruthy()
+
+        decoration.update(type: 'highlight', class: 'new-test-highlight')
+        runSetImmediateCallbacks()
+
+        expect(node.querySelector('.test-highlight')).toBeFalsy()
+        expect(node.querySelector('.new-test-highlight')).toBeTruthy()
+
   describe "hidden input field", ->
     it "renders the hidden input field at the position of the last cursor if the cursor is on screen and the editor is focused", ->
       editor.setVerticalScrollMargin(0)
diff --git a/src/decoration.coffee b/src/decoration.coffee
index d7289cd04..6b7bf21f6 100644
--- a/src/decoration.coffee
+++ b/src/decoration.coffee
@@ -24,7 +24,11 @@ class Decoration
     @emit 'destoryed'
 
   update: (newParams) ->
-    # TODO: implement
+    oldParams = @params
+    @params = newParams
+    @params.id = @id
+    @displayBuffer.decorationUpdated(this)
+    @emit 'updated', {oldParams, newParams}
 
   getParams: ->
     @params
diff --git a/src/display-buffer.coffee b/src/display-buffer.coffee
index 6ce6e4455..fa63c14d5 100644
--- a/src/display-buffer.coffee
+++ b/src/display-buffer.coffee
@@ -814,6 +814,9 @@ class DisplayBuffer extends Model
     delete @decorationMarkerChangedSubscriptions[marker.id]
     delete @decorationMarkerDestroyedSubscriptions[marker.id]
 
+  decorationUpdated: (decoration) ->
+    @emit 'decoration-updated', decoration
+
   # Retrieves a {DisplayBufferMarker} based on its id.
   #
   # id - A {Number} representing a marker id
diff --git a/src/editor-component.coffee b/src/editor-component.coffee
index 53a3b79c9..bacaf4cdb 100644
--- a/src/editor-component.coffee
+++ b/src/editor-component.coffee
@@ -332,6 +332,7 @@ EditorComponent = React.createClass
     @subscribe editor, 'decoration-added', @onDecorationChanged
     @subscribe editor, 'decoration-removed', @onDecorationChanged
     @subscribe editor, 'decoration-changed', @onDecorationChanged
+    @subscribe editor, 'decoration-updated', @onDecorationChanged
     @subscribe editor, 'character-widths-changed', @onCharacterWidthsChanged
     @subscribe editor.$scrollTop.changes, @onScrollTopChanged
     @subscribe editor.$scrollLeft.changes, @requestUpdate
diff --git a/src/editor.coffee b/src/editor.coffee
index e797fbb9d..a8840bb6b 100644
--- a/src/editor.coffee
+++ b/src/editor.coffee
@@ -219,6 +219,7 @@ class Editor extends Model
     @subscribe @displayBuffer, "decoration-added", (args...) => @emit 'decoration-added', args...
     @subscribe @displayBuffer, "decoration-removed", (args...) => @emit 'decoration-removed', args...
     @subscribe @displayBuffer, "decoration-changed", (args...) => @emit 'decoration-changed', args...
+    @subscribe @displayBuffer, "decoration-updated", (args...) => @emit 'decoration-updated', args...
     @subscribe @displayBuffer, "character-widths-changed", (changeCount) => @emit 'character-widths-changed', changeCount
 
   getViewClass: ->