diff --git a/src/ol/has.js b/src/ol/has.js
index b68ea55867..8be8bd5950 100644
--- a/src/ol/has.js
+++ b/src/ol/has.js
@@ -25,7 +25,8 @@ ol.has.CANVAS_LINE_DASH = false;
 
 
 /**
- * True if browser supports Canvas.
+ * True if both the library and browser support Canvas.  Always `false`
+ * if `ol.ENABLE_CANVAS` is set to `false` at compile time.
  * @const
  * @type {boolean}
  * @api stable
@@ -64,7 +65,7 @@ ol.has.DEVICE_ORIENTATION = 'DeviceOrientationEvent' in goog.global;
 
 
 /**
- * True if browser supports DOM.
+ * True if `ol.ENABLE_DOM` is set to `true` at compile time.
  * @const
  * @type {boolean}
  */
@@ -106,7 +107,8 @@ ol.has.MSPOINTER = !!(goog.global.navigator.msPointerEnabled);
 
 
 /**
- * True if browser supports WebGL.
+ * True if both OpenLayers and browser support WebGL.  Always `false`
+ * if `ol.ENABLE_WEBGL` is set to `false` at compile time.
  * @const
  * @type {boolean}
  * @api stable