diff --git a/packages/volto-slate/news/6520.internal b/packages/volto-slate/news/6520.internal
new file mode 100644
index 0000000000..611bdb0abd
--- /dev/null
+++ b/packages/volto-slate/news/6520.internal
@@ -0,0 +1 @@
+Fix extension in files containing JSX. @sneridagh
diff --git a/packages/volto-slate/src/blocks/Table/Cell.test.js b/packages/volto-slate/src/blocks/Table/Cell.test.jsx
similarity index 100%
rename from packages/volto-slate/src/blocks/Table/Cell.test.js
rename to packages/volto-slate/src/blocks/Table/Cell.test.jsx
diff --git a/packages/volto-slate/src/blocks/Table/TableBlockEdit.test.js b/packages/volto-slate/src/blocks/Table/TableBlockEdit.test.jsx
similarity index 100%
rename from packages/volto-slate/src/blocks/Table/TableBlockEdit.test.js
rename to packages/volto-slate/src/blocks/Table/TableBlockEdit.test.jsx
diff --git a/packages/volto-slate/src/blocks/Table/TableBlockView.test.js b/packages/volto-slate/src/blocks/Table/TableBlockView.test.jsx
similarity index 100%
rename from packages/volto-slate/src/blocks/Table/TableBlockView.test.js
rename to packages/volto-slate/src/blocks/Table/TableBlockView.test.jsx
diff --git a/packages/volto-slate/src/blocks/Text/TextBlockEdit.test.js b/packages/volto-slate/src/blocks/Text/TextBlockEdit.test.jsx
similarity index 100%
rename from packages/volto-slate/src/blocks/Text/TextBlockEdit.test.js
rename to packages/volto-slate/src/blocks/Text/TextBlockEdit.test.jsx
diff --git a/packages/volto-slate/src/editor/ui/ToolbarButton.test.js b/packages/volto-slate/src/editor/ui/ToolbarButton.test.jsx
similarity index 100%
rename from packages/volto-slate/src/editor/ui/ToolbarButton.test.js
rename to packages/volto-slate/src/editor/ui/ToolbarButton.test.jsx
diff --git a/packages/volto-slate/src/elementEditor/makeInlineElementPlugin.js b/packages/volto-slate/src/elementEditor/makeInlineElementPlugin.jsx
similarity index 100%
rename from packages/volto-slate/src/elementEditor/makeInlineElementPlugin.js
rename to packages/volto-slate/src/elementEditor/makeInlineElementPlugin.jsx
diff --git a/packages/volto/.eslintrc.core.js b/packages/volto/.eslintrc.core.js
index 41cf953afe..a6b04e24c1 100644
--- a/packages/volto/.eslintrc.core.js
+++ b/packages/volto/.eslintrc.core.js
@@ -11,6 +11,7 @@ if (process.env.VOLTOCONFIG) {
   rules = null;
 } else {
   rules = {
+    'react/jsx-filename-extension': ['warn', { extensions: ['.tsx', '.jsx'] }],
     'no-restricted-imports': [
       'warn',
       {
diff --git a/packages/volto/news/6520.internal b/packages/volto/news/6520.internal
new file mode 100644
index 0000000000..611bdb0abd
--- /dev/null
+++ b/packages/volto/news/6520.internal
@@ -0,0 +1 @@
+Fix extension in files containing JSX. @sneridagh
diff --git a/packages/volto/src/components/manage/Pluggable/Pluggable.stories.js b/packages/volto/src/components/manage/Pluggable/Pluggable.stories.jsx
similarity index 100%
rename from packages/volto/src/components/manage/Pluggable/Pluggable.stories.js
rename to packages/volto/src/components/manage/Pluggable/Pluggable.stories.jsx
diff --git a/packages/volto/src/components/manage/Pluggable/Pluggable.test.js b/packages/volto/src/components/manage/Pluggable/Pluggable.test.jsx
similarity index 100%
rename from packages/volto/src/components/manage/Pluggable/Pluggable.test.js
rename to packages/volto/src/components/manage/Pluggable/Pluggable.test.jsx
diff --git a/packages/volto/src/components/manage/Pluggable/__snapshots__/Pluggable.test.js.snap b/packages/volto/src/components/manage/Pluggable/__snapshots__/Pluggable.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/manage/Pluggable/__snapshots__/Pluggable.test.js.snap
rename to packages/volto/src/components/manage/Pluggable/__snapshots__/Pluggable.test.jsx.snap
diff --git a/packages/volto/src/components/manage/UniversalLink/UniversalLink.stories.js b/packages/volto/src/components/manage/UniversalLink/UniversalLink.stories.jsx
similarity index 100%
rename from packages/volto/src/components/manage/UniversalLink/UniversalLink.stories.js
rename to packages/volto/src/components/manage/UniversalLink/UniversalLink.stories.jsx
diff --git a/packages/volto/src/components/manage/Widgets/ObjectBrowserWidget.stories.js b/packages/volto/src/components/manage/Widgets/ObjectBrowserWidget.stories.jsx
similarity index 100%
rename from packages/volto/src/components/manage/Widgets/ObjectBrowserWidget.stories.js
rename to packages/volto/src/components/manage/Widgets/ObjectBrowserWidget.stories.jsx
diff --git a/packages/volto/src/components/manage/Widgets/ObjectListWidget.stories.js b/packages/volto/src/components/manage/Widgets/ObjectListWidget.stories.jsx
similarity index 100%
rename from packages/volto/src/components/manage/Widgets/ObjectListWidget.stories.js
rename to packages/volto/src/components/manage/Widgets/ObjectListWidget.stories.jsx
diff --git a/packages/volto/src/components/manage/Widgets/ObjectListWidget.test.js b/packages/volto/src/components/manage/Widgets/ObjectListWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/manage/Widgets/ObjectListWidget.test.js
rename to packages/volto/src/components/manage/Widgets/ObjectListWidget.test.jsx
diff --git a/packages/volto/src/components/manage/Widgets/VocabularyTermsWidget.stories.js b/packages/volto/src/components/manage/Widgets/VocabularyTermsWidget.stories.jsx
similarity index 100%
rename from packages/volto/src/components/manage/Widgets/VocabularyTermsWidget.stories.js
rename to packages/volto/src/components/manage/Widgets/VocabularyTermsWidget.stories.jsx
diff --git a/packages/volto/src/components/manage/Widgets/__snapshots__/ObjectListWidget.test.js.snap b/packages/volto/src/components/manage/Widgets/__snapshots__/ObjectListWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/manage/Widgets/__snapshots__/ObjectListWidget.test.js.snap
rename to packages/volto/src/components/manage/Widgets/__snapshots__/ObjectListWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Avatar/Avatar.stories.js b/packages/volto/src/components/theme/Avatar/Avatar.stories.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Avatar/Avatar.stories.js
rename to packages/volto/src/components/theme/Avatar/Avatar.stories.jsx
diff --git a/packages/volto/src/components/theme/Navigation/ContextNavigation.stories.js b/packages/volto/src/components/theme/Navigation/ContextNavigation.stories.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Navigation/ContextNavigation.stories.js
rename to packages/volto/src/components/theme/Navigation/ContextNavigation.stories.jsx
diff --git a/packages/volto/src/components/theme/Navigation/withContentNavigation.js b/packages/volto/src/components/theme/Navigation/withContentNavigation.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Navigation/withContentNavigation.js
rename to packages/volto/src/components/theme/Navigation/withContentNavigation.jsx
diff --git a/packages/volto/src/components/theme/PreviewImage/PreviewImage.test.js b/packages/volto/src/components/theme/PreviewImage/PreviewImage.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/PreviewImage/PreviewImage.test.js
rename to packages/volto/src/components/theme/PreviewImage/PreviewImage.test.jsx
diff --git a/packages/volto/src/components/theme/PreviewImage/__snapshots__/PreviewImage.test.js.snap b/packages/volto/src/components/theme/PreviewImage/__snapshots__/PreviewImage.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/PreviewImage/__snapshots__/PreviewImage.test.js.snap
rename to packages/volto/src/components/theme/PreviewImage/__snapshots__/PreviewImage.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Title/Title.stories.js b/packages/volto/src/components/theme/Title/Title.stories.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Title/Title.stories.js
rename to packages/volto/src/components/theme/Title/Title.stories.jsx
diff --git a/packages/volto/src/components/theme/Widgets/ArrayWidget.test.js b/packages/volto/src/components/theme/Widgets/ArrayWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/ArrayWidget.test.js
rename to packages/volto/src/components/theme/Widgets/ArrayWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/BooleanWidget.test.js b/packages/volto/src/components/theme/Widgets/BooleanWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/BooleanWidget.test.js
rename to packages/volto/src/components/theme/Widgets/BooleanWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/DateWidget.test.js b/packages/volto/src/components/theme/Widgets/DateWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/DateWidget.test.js
rename to packages/volto/src/components/theme/Widgets/DateWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/DatetimeWidget.test.js b/packages/volto/src/components/theme/Widgets/DatetimeWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/DatetimeWidget.test.js
rename to packages/volto/src/components/theme/Widgets/DatetimeWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/DescriptionWidget.test.js b/packages/volto/src/components/theme/Widgets/DescriptionWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/DescriptionWidget.test.js
rename to packages/volto/src/components/theme/Widgets/DescriptionWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/EmailWidget.test.js b/packages/volto/src/components/theme/Widgets/EmailWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/EmailWidget.test.js
rename to packages/volto/src/components/theme/Widgets/EmailWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/FileWidget.test.js b/packages/volto/src/components/theme/Widgets/FileWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/FileWidget.test.js
rename to packages/volto/src/components/theme/Widgets/FileWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/ImageWidget.test.js b/packages/volto/src/components/theme/Widgets/ImageWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/ImageWidget.test.js
rename to packages/volto/src/components/theme/Widgets/ImageWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/PasswordWidget.test.js b/packages/volto/src/components/theme/Widgets/PasswordWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/PasswordWidget.test.js
rename to packages/volto/src/components/theme/Widgets/PasswordWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/RelationWidget.test.js b/packages/volto/src/components/theme/Widgets/RelationWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/RelationWidget.test.js
rename to packages/volto/src/components/theme/Widgets/RelationWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/RelationsWidget.test.js b/packages/volto/src/components/theme/Widgets/RelationsWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/RelationsWidget.test.js
rename to packages/volto/src/components/theme/Widgets/RelationsWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/RichTextWidget.test.js b/packages/volto/src/components/theme/Widgets/RichTextWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/RichTextWidget.test.js
rename to packages/volto/src/components/theme/Widgets/RichTextWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/SelectWidget.test.js b/packages/volto/src/components/theme/Widgets/SelectWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/SelectWidget.test.js
rename to packages/volto/src/components/theme/Widgets/SelectWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/TextWidget.test.js b/packages/volto/src/components/theme/Widgets/TextWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/TextWidget.test.js
rename to packages/volto/src/components/theme/Widgets/TextWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/TitleWidget.test.js b/packages/volto/src/components/theme/Widgets/TitleWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/TitleWidget.test.js
rename to packages/volto/src/components/theme/Widgets/TitleWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/TokenWidget.test.js b/packages/volto/src/components/theme/Widgets/TokenWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/TokenWidget.test.js
rename to packages/volto/src/components/theme/Widgets/TokenWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/UrlWidget.test.js b/packages/volto/src/components/theme/Widgets/UrlWidget.test.jsx
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/UrlWidget.test.js
rename to packages/volto/src/components/theme/Widgets/UrlWidget.test.jsx
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/ArrayWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/ArrayWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/ArrayWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/ArrayWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/BooleanWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/BooleanWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/BooleanWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/BooleanWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/DateWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/DateWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/DateWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/DateWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/DatetimeWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/DatetimeWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/DatetimeWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/DatetimeWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/DescriptionWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/DescriptionWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/DescriptionWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/DescriptionWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/EmailWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/EmailWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/EmailWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/EmailWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/FileWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/FileWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/FileWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/FileWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/ImageWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/ImageWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/ImageWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/ImageWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/PasswordWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/PasswordWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/PasswordWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/PasswordWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/RelationWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/RelationWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/RelationWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/RelationWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/RelationsWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/RelationsWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/RelationsWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/RelationsWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/RichTextWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/RichTextWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/RichTextWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/RichTextWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/SelectWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/SelectWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/SelectWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/SelectWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/TextWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/TextWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/TextWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/TextWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/TitleWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/TitleWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/TitleWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/TitleWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/TokenWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/TokenWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/TokenWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/TokenWidget.test.jsx.snap
diff --git a/packages/volto/src/components/theme/Widgets/__snapshots__/UrlWidget.test.js.snap b/packages/volto/src/components/theme/Widgets/__snapshots__/UrlWidget.test.jsx.snap
similarity index 100%
rename from packages/volto/src/components/theme/Widgets/__snapshots__/UrlWidget.test.js.snap
rename to packages/volto/src/components/theme/Widgets/__snapshots__/UrlWidget.test.jsx.snap
diff --git a/packages/volto/src/helpers/AsyncConnect/AsyncConnect.test.js b/packages/volto/src/helpers/AsyncConnect/AsyncConnect.test.jsx
similarity index 100%
rename from packages/volto/src/helpers/AsyncConnect/AsyncConnect.test.js
rename to packages/volto/src/helpers/AsyncConnect/AsyncConnect.test.jsx
diff --git a/packages/volto/src/helpers/Extensions/__snapshots__/withBlockExtensions.test.js.snap b/packages/volto/src/helpers/Extensions/__snapshots__/withBlockExtensions.test.jsx.snap
similarity index 100%
rename from packages/volto/src/helpers/Extensions/__snapshots__/withBlockExtensions.test.js.snap
rename to packages/volto/src/helpers/Extensions/__snapshots__/withBlockExtensions.test.jsx.snap
diff --git a/packages/volto/src/helpers/Extensions/withBlockExtensions.test.js b/packages/volto/src/helpers/Extensions/withBlockExtensions.test.jsx
similarity index 100%
rename from packages/volto/src/helpers/Extensions/withBlockExtensions.test.js
rename to packages/volto/src/helpers/Extensions/withBlockExtensions.test.jsx
diff --git a/packages/volto/src/helpers/Utils/Utils.test.js b/packages/volto/src/helpers/Utils/Utils.test.jsx
similarity index 100%
rename from packages/volto/src/helpers/Utils/Utils.test.js
rename to packages/volto/src/helpers/Utils/Utils.test.jsx