     @lineHeight * @model.getScreenLineCount()
 
   getBlockDecorationsHeight: ->
-    sizes = Array.from(@blockDecorationsDimensions.values())
+    sizes = Array.from(@blockDecorationsDimensionsById.values())
     sum = (a, b) -> a + b
     height = sizes.map((size) -> size.height).reduce(sum, 0)
     height

    @lineDecorationsByScreenRow = {}
    @lineNumberDecorationsByScreenRow = {}
    @customGutterDecorationsByGutterName = {}
    @blockDecorationsDimensions = new Map
    @screenRowsToMeasure = []
    @transferMeasurementsToModel()
    @transferMeasurementsFromModel()

      @emitDidUpdateState()

  setBlockDecorationSize: (decoration, width, height) ->
    @blockDecorationsDimensionsById.set(decoration.id, {width, height})

    @shouldUpdateBlockDecorations = true
    @shouldUpdateVerticalScrollState = true
