diff --git a/src/ol/style/line.js b/src/ol/style/line.js
index 7d8519067f..1f8d4bea80 100644
--- a/src/ol/style/line.js
+++ b/src/ol/style/line.js
@@ -48,9 +48,9 @@ ol.style.LineLiteral.prototype.equals = function(lineLiteral) {
 
 
 /**
- * @typedef {{strokeStyle: (string|ol.Expression),
- *            strokeWidth: (number|ol.Expression),
- *            opacity: (number|ol.Expression)}}
+ * @typedef {{strokeStyle: (string|ol.Expression|undefined),
+ *            strokeWidth: (number|ol.Expression|undefined),
+ *            opacity: (number|ol.Expression|undefined)}}
  */
 ol.style.LineOptions;
 
diff --git a/src/ol/style/polygon.js b/src/ol/style/polygon.js
index 5886ccf474..7a126abd99 100644
--- a/src/ol/style/polygon.js
+++ b/src/ol/style/polygon.js
@@ -53,10 +53,10 @@ ol.style.PolygonLiteral.prototype.equals = function(polygonLiteral) {
 
 
 /**
- * @typedef {{fillStyle: (string|ol.Expression),
- *            strokeStyle: (string|ol.Expression),
- *            strokeWidth: (number|ol.Expression),
- *            opacity: (number|ol.Expression)}}
+ * @typedef {{fillStyle: (string|ol.Expression|undefined),
+ *            strokeStyle: (string|ol.Expression|undefined),
+ *            strokeWidth: (number|ol.Expression|undefined),
+ *            opacity: (number|ol.Expression|undefined)}}
  */
 ol.style.PolygonOptions;
 
diff --git a/src/ol/style/shape.js b/src/ol/style/shape.js
index 92c407c452..6fe00005e0 100644
--- a/src/ol/style/shape.js
+++ b/src/ol/style/shape.js
@@ -71,12 +71,12 @@ ol.style.ShapeLiteral.prototype.equals = function(shapeLiteral) {
 
 
 /**
- * @typedef {{type: (ol.style.ShapeType),
- *            size: (number|ol.Expression),
- *            fillStyle: (string|ol.Expression),
- *            strokeStyle: (string|ol.Expression),
- *            strokeWidth: (number|ol.Expression),
- *            opacity: (number|ol.Expression)}}
+ * @typedef {{type: (ol.style.ShapeType|undefined),
+ *            size: (number|ol.Expression|undefined),
+ *            fillStyle: (string|ol.Expression|undefined),
+ *            strokeStyle: (string|ol.Expression|undefined),
+ *            strokeWidth: (number|ol.Expression|undefined),
+ *            opacity: (number|ol.Expression|undefined)}}
  */
 ol.style.ShapeOptions;