diff --git a/src/imageuploadcommand.js b/src/imageuploadcommand.js
index 72f4d08..aaee691 100644
--- a/src/imageuploadcommand.js
+++ b/src/imageuploadcommand.js
@@ -10,7 +10,7 @@ import ModelPosition from '@ckeditor/ckeditor5-engine/src/model/position';
 import ModelSelection from '@ckeditor/ckeditor5-engine/src/model/selection';
 import FileRepository from './filerepository';
 import { isImageType } from './utils';
-import Command from '@ckeditor/ckeditor5-core/src/command/command';
+import Command from '@ckeditor/ckeditor5-core/src/command';
 
 /**
  * @module upload/imageuploadcommand
@@ -19,19 +19,19 @@ import Command from '@ckeditor/ckeditor5-core/src/command/command';
 /**
  * Image upload command.
  *
- * @extends module:core/command/command~Command
+ * @extends module:core/command~Command
  */
 export default class ImageUploadCommand extends Command {
 	/**
-	 * Executes command.
+	 * Executes the command.
 	 *
-	 * @protected
+	 * @fires execute
 	 * @param {Object} options Options for executed command.
 	 * @param {File} options.file Image file to upload.
 	 * @param {module:engine/model/batch~Batch} [options.batch] Batch to collect all the change steps.
 	 * New batch will be created if this option is not set.
 	 */
-	_doExecute( options ) {
+	execute( options ) {
 		const editor = this.editor;
 		const doc = editor.document;
 		const batch = options.batch || doc.batch();
diff --git a/src/imageuploadengine.js b/src/imageuploadengine.js
index fc671f2..856b099 100644
--- a/src/imageuploadengine.js
+++ b/src/imageuploadengine.js
@@ -41,7 +41,7 @@ export default class ImageUploadEngine extends Plugin {
 		schema.requireAttributes( 'image', [ 'uploadId' ] );
 
 		// Register imageUpload command.
-		editor.commands.set( 'imageUpload', new ImageUploadCommand( editor ) );
+		editor.commands.add( 'imageUpload', new ImageUploadCommand( editor ) );
 
 		// Execute imageUpload command when image is dropped or pasted.
 		editor.editing.view.on( 'clipboardInput', ( evt, data ) => {
diff --git a/tests/imageuploadcommand.js b/tests/imageuploadcommand.js
index 02c5fda..31b1e86 100644
--- a/tests/imageuploadcommand.js
+++ b/tests/imageuploadcommand.js
@@ -37,12 +37,12 @@ describe( 'ImageUploadCommand', () => {
 		} );
 	} );
 
-	describe( '_doExecute', () => {
+	describe( 'execute()', () => {
 		it( 'should insert image', () => {
 			const file = createNativeFileMock();
 			setModelData( document, '<paragraph>[]foo</paragraph>' );
 
-			command._doExecute( { file } );
+			command.execute( { file } );
 
 			const id = fileRepository.getLoader( file ).id;
 			expect( getModelData( document ) ).to.equal( `[<image uploadId="${ id }"></image>]<paragraph>foo</paragraph>` );
@@ -52,7 +52,7 @@ describe( 'ImageUploadCommand', () => {
 			const file = createNativeFileMock();
 			setModelData( document, '<paragraph>foo[]</paragraph>' );
 
-			command._doExecute( { file } );
+			command.execute( { file } );
 
 			const id = fileRepository.getLoader( file ).id;
 			expect( getModelData( document ) ).to.equal( `<paragraph>foo</paragraph>[<image uploadId="${ id }"></image>]` );
@@ -62,7 +62,7 @@ describe( 'ImageUploadCommand', () => {
 			const file = createNativeFileMock();
 			setModelData( document, '<paragraph>f{}oo</paragraph>' );
 
-			command._doExecute( { file } );
+			command.execute( { file } );
 
 			const id = fileRepository.getLoader( file ).id;
 			expect( getModelData( document ) ).to.equal( `[<image uploadId="${ id }"></image>]<paragraph>foo</paragraph>` );
@@ -72,7 +72,7 @@ describe( 'ImageUploadCommand', () => {
 			const file = createNativeFileMock();
 			setModelData( document, '[<image src="image.png"></image>]' );
 
-			command._doExecute( { file } );
+			command.execute( { file } );
 
 			const id = fileRepository.getLoader( file ).id;
 			expect( getModelData( document ) ).to.equal( `<image src="image.png"></image>[<image uploadId="${ id }"></image>]` );
@@ -88,7 +88,7 @@ describe( 'ImageUploadCommand', () => {
 
 			setModelData( document, '<other>[]</other>' );
 
-			command._doExecute( { file } );
+			command.execute( { file } );
 
 			expect( getModelData( document ) ).to.equal( '<other>[]</other>' );
 		} );
@@ -97,7 +97,7 @@ describe( 'ImageUploadCommand', () => {
 			const file = createNativeFileMock();
 			file.type = 'audio/mpeg3';
 			setModelData( document, '<paragraph>foo[]</paragraph>' );
-			command._doExecute( { file } );
+			command.execute( { file } );
 
 			expect( getModelData( document ) ).to.equal( '<paragraph>foo[]</paragraph>' );
 		} );
@@ -109,7 +109,7 @@ describe( 'ImageUploadCommand', () => {
 
 			setModelData( document, '<paragraph>[]foo</paragraph>' );
 
-			command._doExecute( { batch, file } );
+			command.execute( { batch, file } );
 			const id = fileRepository.getLoader( file ).id;
 
 			expect( getModelData( document ) ).to.equal( `[<image uploadId="${ id }"></image>]<paragraph>foo</paragraph>` );