diff --git a/lib/BaseViewer.js b/lib/BaseViewer.js
index 0b86b96b..4977e528 100644
--- a/lib/BaseViewer.js
+++ b/lib/BaseViewer.js
@@ -238,8 +238,8 @@ BaseViewer.prototype.open = function(bpmnDiagramOrId, done) {
  * You can use these events to hook into the life-cycle.
  *
  * @param {Object} [options] export options
- * @param {Boolean} [options.format=false] output formatted XML
- * @param {Boolean} [options.preamble=true] output preamble
+ * @param {boolean} [options.format=false] output formatted XML
+ * @param {boolean} [options.preamble=true] output preamble
  *
  * @param {Function} done invoked with (err, xml)
  */
diff --git a/lib/features/modeling/behavior/GroupBehavior.js b/lib/features/modeling/behavior/GroupBehavior.js
index 6a50c2f2..2cba2453 100644
--- a/lib/features/modeling/behavior/GroupBehavior.js
+++ b/lib/features/modeling/behavior/GroupBehavior.js
@@ -100,7 +100,7 @@ export default function GroupBehavior(
    *
    * @param {Array<djs.model.shape>} elements
    * @param {ModdleElement} categoryValue
-   * @return {Boolean}
+   * @return {boolean}
    */
   function isReferenced(elements, categoryValue) {
     return elements.some(function(e) {
diff --git a/lib/features/modeling/util/ModelingUtil.js b/lib/features/modeling/util/ModelingUtil.js
index 27237050..92d14780 100644
--- a/lib/features/modeling/util/ModelingUtil.js
+++ b/lib/features/modeling/util/ModelingUtil.js
@@ -11,7 +11,7 @@ import { is } from '../../../util/ModelUtil';
  * @param {djs.model.Base} element
  * @param {Array<string>} types
  *
- * @return {Boolean}
+ * @return {boolean}
  */
 export function isAny(element, types) {
   return some(types, function(t) {
diff --git a/lib/features/popup-menu/util/TypeUtil.js b/lib/features/popup-menu/util/TypeUtil.js
index 431558d3..3f65d89e 100644
--- a/lib/features/popup-menu/util/TypeUtil.js
+++ b/lib/features/popup-menu/util/TypeUtil.js
@@ -14,7 +14,7 @@ import {
  *
  * @param {djs.model.Base} element
  *
- * @return {Boolean}
+ * @return {boolean}
  */
 export function isDifferentType(element) {
 
diff --git a/lib/features/rules/BpmnRules.js b/lib/features/rules/BpmnRules.js
index bd318c37..bbf222a8 100644
--- a/lib/features/rules/BpmnRules.js
+++ b/lib/features/rules/BpmnRules.js
@@ -201,7 +201,7 @@ BpmnRules.prototype.canCopy = canCopy;
  * Checks if given element can be used for starting connection.
  *
  * @param  {Element} source
- * @return {Boolean}
+ * @return {boolean}
  */
 function canStartConnection(element) {
   if (nonExistingOrLabel(element)) {
@@ -435,7 +435,7 @@ function canConnect(source, target, connection) {
 /**
  * Can an element be dropped into the target element
  *
- * @return {Boolean}
+ * @return {boolean}
  */
 function canDrop(element, target, position) {
 
diff --git a/lib/import/BpmnTreeWalker.js b/lib/import/BpmnTreeWalker.js
index e897d9b8..2b2342b3 100644
--- a/lib/import/BpmnTreeWalker.js
+++ b/lib/import/BpmnTreeWalker.js
@@ -21,7 +21,7 @@ var diRefs = new Refs(
  * @param  {ModdleElement}  element
  * @param  {string}         type
  *
- * @return {Boolean}
+ * @return {boolean}
  */
 function is(element, type) {
   return element.$instanceOf(type);
diff --git a/lib/util/LabelUtil.js b/lib/util/LabelUtil.js
index 5c6513bf..e23a633d 100644
--- a/lib/util/LabelUtil.js
+++ b/lib/util/LabelUtil.js
@@ -17,7 +17,7 @@ export var FLOW_LABEL_INDENT = 15;
  * Returns true if the given semantic has an external label
  *
  * @param {BpmnElement} semantic
- * @return {Boolean} true if has label
+ * @return {boolean} true if has label
  */
 export function isLabelExternal(semantic) {
   return is(semantic, 'bpmn:Event') ||
@@ -35,7 +35,7 @@ export function isLabelExternal(semantic) {
  * Returns true if the given element has an external label
  *
  * @param {djs.model.shape} element
- * @return {Boolean} true if has label
+ * @return {boolean} true if has label
  */
 export function hasExternalLabel(element) {
   return isLabel(element.label);
diff --git a/lib/util/ModelUtil.js b/lib/util/ModelUtil.js
index 3a0a7773..d4506f8a 100644
--- a/lib/util/ModelUtil.js
+++ b/lib/util/ModelUtil.js
@@ -4,7 +4,7 @@
  * @param  {djs.model.Base|ModdleElement} element
  * @param  {string} type
  *
- * @return {Boolean}
+ * @return {boolean}
  */
 export function is(element, type) {
   var bo = getBusinessObject(element);