diff --git a/packages/ckeditor5-list/src/listformatting.ts b/packages/ckeditor5-list/src/listformatting.ts
index f72dd31597e..624088590b8 100644
--- a/packages/ckeditor5-list/src/listformatting.ts
+++ b/packages/ckeditor5-list/src/listformatting.ts
@@ -242,6 +242,9 @@ function getSingleListItemConsistentFormat( model: Model, listItem: ModelElement
 					attributesToCheck.delete( attributeKey );
 					valuesMap[ attributeKey ] = undefined;
 				}
+			} else if ( !( attributeKey in valuesMap ) ) {
+				// Store it so a format would be removed when all items in the given list item does not allow that formatting.
+				valuesMap[ attributeKey ] = undefined;
 			}
 		}
 
diff --git a/packages/ckeditor5-list/tests/listformatting.js b/packages/ckeditor5-list/tests/listformatting.js
index 229bc05ab9d..75b73fcb450 100644
--- a/packages/ckeditor5-list/tests/listformatting.js
+++ b/packages/ckeditor5-list/tests/listformatting.js
@@ -8,6 +8,7 @@ import { Paragraph } from '@ckeditor/ckeditor5-paragraph/src/paragraph.js';
 import { Plugin } from '@ckeditor/ckeditor5-core/src/plugin.js';
 import { BlockQuoteEditing } from '@ckeditor/ckeditor5-block-quote';
 import { RemoveFormatEditing } from '@ckeditor/ckeditor5-remove-format';
+import { CodeBlockEditing } from '@ckeditor/ckeditor5-code-block';
 import { _setModelData, _getModelData } from '@ckeditor/ckeditor5-engine/src/dev-utils/model.js';
 import { testUtils } from '@ckeditor/ckeditor5-core/tests/_utils/utils.js';
 
@@ -26,7 +27,7 @@ describe( 'ListFormatting', () => {
 
 	beforeEach( async () => {
 		editor = await VirtualTestEditor.create( {
-			plugins: [ ListFormatting, Paragraph, BlockQuoteEditing, RemoveFormatEditing, MyPlugin, MyPlugin2 ]
+			plugins: [ ListFormatting, Paragraph, BlockQuoteEditing, CodeBlockEditing, RemoveFormatEditing, MyPlugin, MyPlugin2 ]
 		} );
 
 		model = editor.model;
@@ -393,6 +394,29 @@ describe( 'ListFormatting', () => {
 				);
 			} );
 
+			it( 'should not change attribute on formatted li if inserted inline object does not accept formatting', () => {
+				_setModelData( model,
+					'<paragraph listIndent="0" listItemFormat="foo" listItemId="a" listType="numbered">' +
+						'<$text inlineFormat="foo">foo[]</$text>' +
+					'</paragraph>'
+				);
+
+				model.schema.extend( 'inlineObject', {
+					disallowAttributes: 'inlineFormat'
+				} );
+
+				model.change( writer => {
+					writer.insert( writer.createElement( 'inlineObject' ), docSelection.getFirstPosition() );
+				} );
+
+				expect( _getModelData( model, { withoutSelection: true } ) ).to.equalMarkup(
+					'<paragraph listIndent="0" listItemFormat="foo" listItemId="a" listType="numbered">' +
+						'<$text inlineFormat="foo">foo</$text>' +
+						'<inlineObject></inlineObject>' +
+					'</paragraph>'
+				);
+			} );
+
 			it( 'should remove attribute from formatted li if inserted text has different format', () => {
 				_setModelData( model,
 					'<paragraph listIndent="0" listItemFormat="foo" listItemId="a" listType="numbered">' +
@@ -486,6 +510,37 @@ describe( 'ListFormatting', () => {
 					'</blockQuote>'
 				);
 			} );
+
+			it( 'should reset marker formatting when list item block changed to code block', () => {
+				_setModelData( model,
+					'<paragraph listIndent="0" listItemId="a" listType="numbered">' +
+						'<$text inlineFormat="foo">fo[]o</$text>' +
+					'</paragraph>' +
+					'<paragraph listIndent="0" listItemId="b" listType="numbered">' +
+						'<$text inlineFormat="foo">bar</$text>' +
+					'</paragraph>'
+				);
+
+				expect( _getModelData( model, { withoutSelection: true } ) ).to.equalMarkup(
+					'<paragraph listIndent="0" listItemFormat="foo" listItemId="a" listType="numbered">' +
+						'<$text inlineFormat="foo">foo</$text>' +
+					'</paragraph>' +
+					'<paragraph listIndent="0" listItemFormat="foo" listItemId="b" listType="numbered">' +
+						'<$text inlineFormat="foo">bar</$text>' +
+					'</paragraph>'
+				);
+
+				editor.execute( 'codeBlock' );
+
+				expect( _getModelData( model, { withoutSelection: true } ) ).to.equalMarkup(
+					'<codeBlock language="plaintext" listIndent="0" listItemId="a" listType="numbered">' +
+						'foo' +
+					'</codeBlock>' +
+					'<paragraph listIndent="0" listItemFormat="foo" listItemId="b" listType="numbered">' +
+						'<$text inlineFormat="foo">bar</$text>' +
+					'</paragraph>'
+				);
+			} );
 		} );
 
 		describe( 'other elements handling (block objects, inline objects)', () => {