diff --git a/lib/features/auto-place/AutoPlace.js b/lib/features/auto-place/AutoPlace.js
index 604c6a8c3..50d9e2485 100644
--- a/lib/features/auto-place/AutoPlace.js
+++ b/lib/features/auto-place/AutoPlace.js
@@ -44,6 +44,7 @@ export default function AutoPlace(eventBus, modeling, canvas) {
    *
    * @param {Shape} source
    * @param {Shape} shape
+   * @param {any} [hints={}]
    *
    * @return {Shape} appended shape
    */
diff --git a/lib/features/create/Create.js b/lib/features/create/Create.js
index b8c7422e9..5720bb9dd 100644
--- a/lib/features/create/Create.js
+++ b/lib/features/create/Create.js
@@ -270,6 +270,11 @@ export default function Create(
 
   // API //////////
 
+  /**
+   * @param event
+   * @param elements
+   * @param {any} [context={}]
+   */
   this.start = function(event, elements, context) {
     if (!isArray(elements)) {
       elements = [ elements ];
diff --git a/lib/navigation/zoomscroll/ZoomScroll.js b/lib/navigation/zoomscroll/ZoomScroll.js
index a34313357..c2d8c5b4d 100644
--- a/lib/navigation/zoomscroll/ZoomScroll.js
+++ b/lib/navigation/zoomscroll/ZoomScroll.js
@@ -179,7 +179,7 @@ ZoomScroll.prototype._handleWheel = function handleWheel(event) {
  * Zoom with fixed step size.
  *
  * @param {number} delta Zoom delta (1 for zooming in, -1 for zooming out).
- * @param {Point} position
+ * @param {Point} [position]
  */
 ZoomScroll.prototype.stepZoom = function stepZoom(delta, position) {
 
@@ -193,7 +193,7 @@ ZoomScroll.prototype.stepZoom = function stepZoom(delta, position) {
  * Zoom in/out given a step size.
  *
  * @param {number} delta
- * @param {Point} position
+ * @param {Point} [position]
  * @param {number} stepSize
  */
 ZoomScroll.prototype._zoom = function(delta, position, stepSize) {
diff --git a/lib/util/Text.js b/lib/util/Text.js
index 88e21d2f1..953e3b429 100644
--- a/lib/util/Text.js
+++ b/lib/util/Text.js
@@ -295,7 +295,7 @@ function getHelperSvg() {
 /**
  * Creates a new label utility
  *
- * @param {TextConfig} config
+ * @param {TextConfig} [config]
  */
 export default function Text(config) {