diff --git a/externs/olx.js b/externs/olx.js
index 51f8a54c38..c65ba8247b 100644
--- a/externs/olx.js
+++ b/externs/olx.js
@@ -4537,8 +4537,8 @@ olx.source.RasterOptions.prototype.lib;
 /**
  * By default, operations will be run in a single worker thread.  To avoid using
  * workers altogether, set `threads: 0`.  For pixel operations, operations can
- * be run in multiple worker threads.  Note that there some additional overhead
- * in transferring data to multiple workers, and that depending on the user's
+ * be run in multiple worker threads.  Note that there is additional overhead in
+ * transferring data to multiple workers, and that depending on the user's
  * system, it may not be possible to parallelize the work.
  * @type {number|undefined}
  * @api
diff --git a/src/ol/raster/operation.js b/src/ol/raster/operation.js
index 340bc37ff7..9ebd914e50 100644
--- a/src/ol/raster/operation.js
+++ b/src/ol/raster/operation.js
@@ -24,7 +24,7 @@ ol.raster.OperationType = {
  * an array of the same.  The operations are called with a second "data"
  * argument, which can be used for storage.  The data object is accessible
  * from raster events, where it can be initialized in "beforeoperations" and
- * accessed again in "afteroperations."
+ * accessed again in "afteroperations".
  *
  * @typedef {function((Array.<ol.raster.Pixel>|Array.<ImageData>), Object):
  *     (Array.<ol.raster.Pixel>|Array.<ImageData>)}
diff --git a/src/ol/source/rastersource.js b/src/ol/source/rastersource.js
index 46b4d13502..c13a4c66d3 100644
--- a/src/ol/source/rastersource.js
+++ b/src/ol/source/rastersource.js
@@ -28,9 +28,9 @@ goog.require('ol.source.Tile');
 
 /**
  * @classdesc
- * An source that transforms data from any number of input sources source using
- * an array of {@link ol.raster.Operation} functions to transform input pixel
- * values into output pixel values.
+ * A source that transforms data from any number of input sources using an array
+ * of {@link ol.raster.Operation} functions to transform input pixel values into
+ * output pixel values.
  *
  * @constructor
  * @extends {ol.source.Image}