diff --git a/src/ol/format/kmlformat.js b/src/ol/format/kmlformat.js
index 037c7a6007..460032422a 100644
--- a/src/ol/format/kmlformat.js
+++ b/src/ol/format/kmlformat.js
@@ -1869,7 +1869,9 @@ ol.format.KML.prototype.readSharedStyleMap_ = function(node, objectStack) {
 
 
 /**
- * Read the first feature from a KML source.
+ * Read the first feature from a KML source. MultiGeometries are converted into
+ * GeometryCollections if they are a mix of geometry types, and into MultiPoint/
+ * MultiLineString/MultiPolygon if they are all of the same type.
  *
  * @function
  * @param {Document|Node|Object|string} source Source.
@@ -1902,7 +1904,9 @@ ol.format.KML.prototype.readFeatureFromNode = function(node, opt_options) {
 
 
 /**
- * Read all features from a KML source.
+ * Read all features from a KML source. MultiGeometries are converted into
+ * GeometryCollections if they are a mix of geometry types, and into MultiPoint/
+ * MultiLineString/MultiPolygon if they are all of the same type.
  *
  * @function
  * @param {Document|Node|Object|string} source Source.
@@ -2961,7 +2965,8 @@ ol.format.KML.OUTER_BOUNDARY_NODE_FACTORY_ =
 
 
 /**
- * Encode an array of features in the KML format.
+ * Encode an array of features in the KML format. GeometryCollections, MultiPoints,
+ * MultiLineStrings, and MultiPolygons are output as MultiGeometries.
  *
  * @function
  * @param {Array.<ol.Feature>} features Features.
@@ -2973,7 +2978,8 @@ ol.format.KML.prototype.writeFeatures;
 
 
 /**
- * Encode an array of features in the KML format as an XML node.
+ * Encode an array of features in the KML format as an XML node. GeometryCollections,
+ * MultiPoints, MultiLineStrings, and MultiPolygons are output as MultiGeometries.
  *
  * @param {Array.<ol.Feature>} features Features.
  * @param {olx.format.WriteOptions=} opt_options Options.