diff --git a/js/giraffe.js b/js/giraffe.js
index fc84584..acd0ea8 100644
--- a/js/giraffe.js
+++ b/js/giraffe.js
@@ -284,7 +284,7 @@ createGraph = function(anchor, metric) {
     null_as: metric.null_as === void 0 ? null : metric.null_as,
     renderer: metric.renderer || 'area',
     interpolation: metric.interpolation || 'step-before',
-    offset: metric.offset || 'value',
+    offset: metric.offset || 'zero',
     unstack: metric.unstack === void 0 ? unstackable : metric.unstack,
     stroke: metric.stroke === false ? false : true,
     stroke_fn: typeof metric.stroke === "function" ? metric.stroke : void 0,
diff --git a/js/src/giraffe.coffee b/js/src/giraffe.coffee
index fa89bb9..1c7702c 100644
--- a/js/src/giraffe.coffee
+++ b/js/src/giraffe.coffee
@@ -193,7 +193,7 @@ createGraph = (anchor, metric) ->
     null_as: if metric.null_as is undefined then null else metric.null_as
     renderer: metric.renderer || 'area'
     interpolation: metric.interpolation || 'step-before'
-    offset: metric.offset || 'value'
+    offset: metric.offset || 'zero'
     unstack: if metric.unstack is undefined then unstackable else metric.unstack
     stroke: if metric.stroke is false then false else true
     stroke_fn: metric.stroke if typeof metric.stroke is "function"