diff --git a/i18n/en.json b/i18n/en.json
index 6df38c5c..f2e1f408 100644
--- a/i18n/en.json
+++ b/i18n/en.json
@@ -56,6 +56,7 @@
 	"gadgets-validate-invalidnamespaces": "The following namespace {{PLURAL:$2|number does|numbers do}} not exist: $1",
 	"gadgets-validate-invalidtargets": "Allowed values for targets are: mobile, desktop. Found invalid {{PLURAL:$2|value|values}}: $1",
 	"gadgets-validate-invalidtitle": "Page title \"$1\" is invalid",
+	"gadgets-validate-unknownpages": "Contains one or more pages without .js, .css or .json suffix. They would not be used.",
 	"gadgets-validate-nopage": "Page \"$1\" does not exist.",
 	"right-gadgets-definition-edit": "Edit gadget definitions",
 	"action-gadgets-definition-edit": "edit this gadget definition",
diff --git a/i18n/qqq.json b/i18n/qqq.json
index 190cb804..6cdf1103 100644
--- a/i18n/qqq.json
+++ b/i18n/qqq.json
@@ -70,6 +70,7 @@
 	"gadgets-validate-invalidnamespaces": "Warning message to indicate that the namespaces are not recognised. Parameters:\n* $1 - comma separated list of invalid namespaces, $2 - number of items in list $1",
 	"gadgets-validate-invalidtargets": "Warning message to indicate that the targets are not recognised. Parameters:\n* $1 - comma separated list of invalid targets, $2 - number of items in list $1",
 	"gadgets-validate-invalidtitle": "Warning message to indicate that the page title is invalid. Parameters:\n* $1 - page name",
+	"gadgets-validate-unknownpages": "Warning message to indicate that pages without .js, .css or .json suffix are not recognised.",
 	"gadgets-validate-nopage": "Warning message to indicate the script/style/json page does not exist. Parameters:\n* $1 - page name",
 	"right-gadgets-definition-edit": "{{doc-right|gadgets-definition-edit}}",
 	"action-gadgets-definition-edit": "{{doc-action|gadgets-definition-edit}}",
diff --git a/includes/Content/GadgetDefinitionContent.php b/includes/Content/GadgetDefinitionContent.php
index 60ba5212..038d5adb 100644
--- a/includes/Content/GadgetDefinitionContent.php
+++ b/includes/Content/GadgetDefinitionContent.php
@@ -49,7 +49,7 @@ class GadgetDefinitionContent extends JsonContent {
 	 * @return string
 	 */
 	public function beautifyJSON() {
-		// @todo we should normalize entries in module.scripts and module.styles
+		// @todo we should normalize entries in module.pages
 		return FormatJson::encode( $this->getAssocArray(), "\t", FormatJson::UTF8_OK );
 	}
 
diff --git a/includes/Content/GadgetDefinitionContentHandler.php b/includes/Content/GadgetDefinitionContentHandler.php
index 70cf5d86..38c40415 100644
--- a/includes/Content/GadgetDefinitionContentHandler.php
+++ b/includes/Content/GadgetDefinitionContentHandler.php
@@ -68,9 +68,7 @@ class GadgetDefinitionContentHandler extends JsonContentHandler {
 				'supportsUrlLoad' => false,
 			],
 			'module' => [
-				'scripts' => [],
-				'styles' => [],
-				'datas' => [],
+				'pages' => [],
 				'peers' => [],
 				'dependencies' => [],
 				'messages' => [],
@@ -91,12 +89,10 @@ class GadgetDefinitionContentHandler extends JsonContentHandler {
 		// Create a deep clone. FIXME: unserialize(serialize()) is hacky.
 		$data = unserialize( serialize( $content->getData()->getValue() ) );
 		if ( $data !== null ) {
-			foreach ( [ 'scripts', 'styles', 'datas' ] as $type ) {
-				if ( isset( $data->module->{$type} ) ) {
-					foreach ( $data->module->{$type} as &$page ) {
-						$title = Title::makeTitleSafe( NS_GADGET, $page );
-						$this->makeLink( $parserOutput, $page, $title );
-					}
+			if ( isset( $data->module->pages ) ) {
+				foreach ( $data->module->pages as &$page ) {
+					$title = Title::makeTitleSafe( NS_GADGET, $page );
+					$this->makeLink( $parserOutput, $page, $title );
 				}
 			}
 			foreach ( $data->module->dependencies as &$dep ) {
diff --git a/includes/Content/GadgetDefinitionValidator.php b/includes/Content/GadgetDefinitionValidator.php
index 832d5e45..f158fd39 100644
--- a/includes/Content/GadgetDefinitionValidator.php
+++ b/includes/Content/GadgetDefinitionValidator.php
@@ -29,9 +29,7 @@ class GadgetDefinitionValidator {
 		'settings.supportsUrlLoad' => [ 'is_bool', 'boolean' ],
 		'settings.requiresES6' => [ 'is_bool', 'boolean' ],
 		'module' => [ 'is_array', 'array' ],
-		'module.scripts' => [ 'is_array', 'array', 'is_string', 'string' ],
-		'module.styles' => [ 'is_array', 'array', 'is_string', 'string' ],
-		'module.datas' => [ 'is_array', 'array', 'is_string', 'string' ],
+		'module.pages' => [ 'is_array', 'array', 'is_string', 'string' ],
 		'module.dependencies' => [ 'is_array', 'array', 'is_string', 'string' ],
 		'module.peers' => [ 'is_array', 'array', 'is_string', 'string' ],
 		'module.messages' => [ 'is_array', 'array', 'is_string', 'string' ],
diff --git a/includes/Content/schema.json b/includes/Content/schema.json
index 24d75d0f..252974ec 100644
--- a/includes/Content/schema.json
+++ b/includes/Content/schema.json
@@ -87,17 +87,9 @@
 			"type": "object",
 			"additionalProperties": false,
 			"properties": {
-				"scripts": {
+				"pages": {
 					"type": "array",
-					"description": "List of JavaScript pages included in this gadget"
-				},
-				"styles": {
-					"type": "array",
-					"description": "List of CSS pages included in this gadget"
-				},
-				"datas": {
-					"type": "array",
-					"description": "List of JSON pages included in this gadget"
+					"description": "List of JS/CSS/JSON pages included in this gadget"
 				},
 				"dependencies": {
 					"type": "array",
diff --git a/includes/Gadget.php b/includes/Gadget.php
index 9589eb1a..5aae2bd9 100644
--- a/includes/Gadget.php
+++ b/includes/Gadget.php
@@ -36,19 +36,15 @@ class Gadget {
 	/**
 	 * Increment this when changing class structure
 	 */
-	public const GADGET_CLASS_VERSION = 15;
+	public const GADGET_CLASS_VERSION = 16;
 
 	public const CACHE_TTL = 86400;
 
-	/** @var string[] */
-	private $scripts = [];
-	/** @var string[] */
-	private $styles = [];
-	/** @var string[] */
-	private $datas = [];
 	/** @var string[] */
 	private $dependencies = [];
 	/** @var string[] */
+	private array $pages = [];
+	/** @var string[] */
 	private $peers = [];
 	/** @var string[] */
 	private $messages = [];
@@ -88,10 +84,8 @@ class Gadget {
 	public function __construct( array $options ) {
 		foreach ( $options as $member => $option ) {
 			switch ( $member ) {
-				case 'scripts':
-				case 'styles':
-				case 'datas':
 				case 'dependencies':
+				case 'pages':
 				case 'peers':
 				case 'messages':
 				case 'name':
@@ -132,13 +126,13 @@ class Gadget {
 		};
 		return [
 			'category' => $data['settings']['category'],
-			'datas' => array_map( $prefixGadgetNs, $data['module']['datas'] ),
 			'dependencies' => $data['module']['dependencies'],
 			'hidden' => $data['settings']['hidden'],
 			'messages' => $data['module']['messages'],
 			'name' => $id,
 			'onByDefault' => $data['settings']['default'],
 			'package' => $data['settings']['package'],
+			'pages' => array_map( $prefixGadgetNs, $data['module']['pages'] ),
 			'peers' => $data['module']['peers'],
 			'requiredActions' => $data['settings']['actions'],
 			'requiredContentModels' => $data['settings']['contentModels'],
@@ -147,8 +141,6 @@ class Gadget {
 			'requiredSkins' => $data['settings']['skins'],
 			'requiresES6' => $data['settings']['requiresES6'],
 			'resourceLoaded' => true,
-			'scripts' => array_map( $prefixGadgetNs, $data['module']['scripts'] ),
-			'styles' => array_map( $prefixGadgetNs, $data['module']['styles'] ),
 			'supportsUrlLoad' => $data['settings']['supportsUrlLoad'],
 			'targets' => $data['settings']['targets'],
 			'type' => $data['module']['type'],
@@ -162,13 +154,13 @@ class Gadget {
 	public function toArray(): array {
 		return [
 			'category' => $this->category,
-			'datas' => $this->datas,
 			'dependencies' => $this->dependencies,
 			'hidden' => $this->hidden,
 			'messages' => $this->messages,
 			'name' => $this->name,
 			'onByDefault' => $this->onByDefault,
 			'package' => $this->package,
+			'pages' => $this->pages,
 			'peers' => $this->peers,
 			'requiredActions' => $this->requiredActions,
 			'requiredContentModels' => $this->requiredContentModels,
@@ -177,8 +169,6 @@ class Gadget {
 			'requiredSkins' => $this->requiredSkins,
 			'requiresES6' => $this->requiresES6,
 			'resourceLoaded' => $this->resourceLoaded,
-			'scripts' => $this->scripts,
-			'styles' => $this->styles,
 			'supportsUrlLoad' => $this->supportsUrlLoad,
 			'targets' => $this->targets,
 			'type' => $this->type,
@@ -291,7 +281,7 @@ class Gadget {
 	 */
 	public function isPackaged(): bool {
 		// A packaged gadget needs to have a main script, so there must be at least one script
-		return $this->package && $this->supportsResourceLoader() && $this->scripts !== [];
+		return $this->package && $this->supportsResourceLoader() && $this->getScripts() !== [];
 	}
 
 	/**
@@ -375,7 +365,7 @@ class Gadget {
 	 * @return bool Whether this gadget has resources that can be loaded via ResourceLoader
 	 */
 	public function hasModule() {
-		return $this->styles || ( $this->supportsResourceLoader() && $this->scripts );
+		return $this->getStyles() || ( $this->supportsResourceLoader() && $this->getScripts() );
 	}
 
 	/**
@@ -389,28 +379,34 @@ class Gadget {
 	 * @return array Array of pages with JS (including namespace)
 	 */
 	public function getScripts() {
-		return $this->scripts;
+		return array_values( array_filter( $this->pages, static function ( $page ) {
+			return str_ends_with( $page, '.js' );
+		} ) );
 	}
 
 	/**
 	 * @return array Array of pages with CSS (including namespace)
 	 */
 	public function getStyles() {
-		return $this->styles;
+		return array_values( array_filter( $this->pages, static function ( $page ) {
+			return str_ends_with( $page, '.css' );
+		} ) );
 	}
 
 	/**
 	 * @return array Array of pages with JSON (including namespace)
 	 */
 	public function getJSONs(): array {
-		return $this->isPackaged() ? $this->datas : [];
+		return array_values( array_filter( $this->pages, static function ( $page ) {
+			return str_ends_with( $page, '.json' );
+		} ) );
 	}
 
 	/**
 	 * @return array Array of all of this gadget's resources
 	 */
 	public function getScriptsAndStyles() {
-		return array_merge( $this->scripts, $this->styles, $this->getJSONs() );
+		return array_merge( $this->getScripts(), $this->getStyles(), $this->getJSONs() );
 	}
 
 	/**
@@ -418,7 +414,7 @@ class Gadget {
 	 * @return string[]
 	 */
 	public function getLegacyScripts() {
-		return $this->supportsResourceLoader() ? [] : $this->scripts;
+		return $this->supportsResourceLoader() ? [] : $this->getScripts();
 	}
 
 	/**
@@ -498,7 +494,7 @@ class Gadget {
 			return $this->type;
 		}
 		// Similar to ResourceLoaderWikiModule default
-		if ( $this->styles && !$this->scripts && !$this->dependencies ) {
+		if ( $this->getStyles() && !$this->getScripts() && !$this->dependencies ) {
 			return 'styles';
 		}
 
@@ -517,18 +513,23 @@ class Gadget {
 			$warnings[] = "gadgets-validate-es6default";
 		}
 
+		// Gadget containing files with uncrecognised suffixes
+		if ( count( array_diff( $this->pages, $this->getScriptsAndStyles() ) ) !== 0 ) {
+			$warnings[] = "gadgets-validate-unknownpages";
+		}
+
 		// Non-package gadget containing JSON files
-		if ( !$this->package && count( $this->datas ) > 0 ) {
+		if ( !$this->package && count( $this->getJSONs() ) > 0 ) {
 			$warnings[] = "gadgets-validate-json";
 		}
 
 		// Package gadget without a script file in it (to serve as entry point)
-		if ( $this->package && count( $this->scripts ) === 0 ) {
+		if ( $this->package && count( $this->getScripts() ) === 0 ) {
 			$warnings[] = "gadgets-validate-noentrypoint";
 		}
 
 		// Gadget with type=styles having non-CSS files
-		if ( $this->type === 'styles' && count( $this->scripts ) > 0 ) {
+		if ( $this->type === 'styles' && count( $this->getScripts() ) > 0 ) {
 			$warnings[] = "gadgets-validate-scriptsnotallowed";
 		}
 
diff --git a/includes/GadgetResourceLoaderModule.php b/includes/GadgetResourceLoaderModule.php
index c836f564..79c53402 100644
--- a/includes/GadgetResourceLoaderModule.php
+++ b/includes/GadgetResourceLoaderModule.php
@@ -61,8 +61,10 @@ class GadgetResourceLoaderModule extends RL\WikiModule {
 			foreach ( $gadget->getScripts() as $script ) {
 				$pages[$script] = [ 'type' => 'script' ];
 			}
-			foreach ( $gadget->getJSONs() as $json ) {
-				$pages[$json] = [ 'type' => 'data' ];
+			if ( $gadget->isPackaged() ) {
+				foreach ( $gadget->getJSONs() as $json ) {
+					$pages[$json] = [ 'type' => 'data' ];
+				}
 			}
 		}
 
diff --git a/includes/MediaWikiGadgetsDefinitionRepo.php b/includes/MediaWikiGadgetsDefinitionRepo.php
index a355db8a..33288a1e 100644
--- a/includes/MediaWikiGadgetsDefinitionRepo.php
+++ b/includes/MediaWikiGadgetsDefinitionRepo.php
@@ -304,14 +304,7 @@ class MediaWikiGadgetsDefinitionRepo extends GadgetRepo {
 
 		foreach ( preg_split( '/\s*\|\s*/', $pages, -1, PREG_SPLIT_NO_EMPTY ) as $page ) {
 			$page = $this->titlePrefix . $page;
-
-			if ( preg_match( '/\.json$/', $page ) ) {
-				$info['datas'][] = $page;
-			} elseif ( preg_match( '/\.js/', $page ) ) {
-				$info['scripts'][] = $page;
-			} elseif ( preg_match( '/\.css/', $page ) ) {
-				$info['styles'][] = $page;
-			}
+			$info['pages'][] = $page;
 		}
 
 		return new Gadget( $info );
diff --git a/tests/phpunit/integration/GadgetDefinitionNamespaceRepoTest.php b/tests/phpunit/integration/GadgetDefinitionNamespaceRepoTest.php
index 45ab9184..3e253934 100644
--- a/tests/phpunit/integration/GadgetDefinitionNamespaceRepoTest.php
+++ b/tests/phpunit/integration/GadgetDefinitionNamespaceRepoTest.php
@@ -13,7 +13,7 @@ class GadgetDefinitionNamespaceRepoTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testGetGadget() {
 		$this->editPage( 'Gadget definition:Test',
-			'{"module":{"scripts":["test.js"]}, "settings":{"default":true}}' );
+			'{"module":{"pages":["test.js"]}, "settings":{"default":true}}' );
 
 		$services = $this->getServiceContainer();
 		$repo = new GadgetDefinitionNamespaceRepo( $services->getMainWANObjectCache(), $services->getRevisionLookup() );
@@ -27,9 +27,9 @@ class GadgetDefinitionNamespaceRepoTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testGetGadgetIds() {
 		$this->editPage( 'Gadget definition:X1',
-			'{"module":{"scripts":["Gadget:test.js"]}, "settings":{"default":true}}' );
+			'{"module":{"pages":["Gadget:test.js"]}, "settings":{"default":true}}' );
 		$this->editPage( 'Gadget definition:X2',
-			'{"module":{"scripts":["Gadget:test.js"]}, "settings":{"default":true}}' );
+			'{"module":{"pages":["Gadget:test.js"]}, "settings":{"default":true}}' );
 
 		$services = $this->getServiceContainer();
 		$wanCache = $services->getMainWANObjectCache();
diff --git a/tests/phpunit/integration/GadgetHooksTest.php b/tests/phpunit/integration/GadgetHooksTest.php
index 4b36ece4..784c9b9f 100644
--- a/tests/phpunit/integration/GadgetHooksTest.php
+++ b/tests/phpunit/integration/GadgetHooksTest.php
@@ -17,7 +17,7 @@ class GadgetHooksTest extends MediaWikiIntegrationTestCase {
 	public function testDefaultGadget() {
 		$services = $this->getServiceContainer();
 		$repo = new StaticGadgetRepo( [
-			'g1' => new Gadget( [ 'name' => 'g1', 'onByDefault' => true, 'styles' => 'test.css' ] ),
+			'g1' => new Gadget( [ 'name' => 'g1', 'onByDefault' => true, 'pages' => [ 'test.css' ] ] ),
 		] );
 		$hooks = new GadgetHooks( $repo, $services->getUserOptionsLookup(), null );
 		$out = new OutputPage( RequestContext::getMain() );
@@ -34,7 +34,7 @@ class GadgetHooksTest extends MediaWikiIntegrationTestCase {
 	public function testEnabledGadget() {
 		$services = $this->getServiceContainer();
 		$repo = new StaticGadgetRepo( [
-			'g1' => new Gadget( [ 'name' => 'g1', 'scripts' => 'test.js', 'resourceLoaded' => true ] ),
+			'g1' => new Gadget( [ 'name' => 'g1', 'pages' => [ 'test.js' ], 'resourceLoaded' => true ] ),
 		] );
 		$hooks = new GadgetHooks( $repo, $services->getUserOptionsLookup(), null );
 		$context = RequestContext::getMain();
@@ -58,9 +58,9 @@ class GadgetHooksTest extends MediaWikiIntegrationTestCase {
 	 */
 	public function testDefaultUserOptions() {
 		$repo = new StaticGadgetRepo( [
-			'g1' => new Gadget( [ 'name' => 'g1', 'styles' => 'test.css', 'onByDefault' => true ] ),
-			'g2' => new Gadget( [ 'name' => 'g2', 'styles' => 'test.css' ] ),
-			'g3' => new Gadget( [ 'name' => 'g3', 'styles' => 'test.css', 'hidden' => true ] ),
+			'g1' => new Gadget( [ 'name' => 'g1', 'pages' => [ 'test.css' ], 'onByDefault' => true ] ),
+			'g2' => new Gadget( [ 'name' => 'g2', 'pages' => [ 'test.css' ] ] ),
+			'g3' => new Gadget( [ 'name' => 'g3', 'pages' => [ 'test.css' ], 'hidden' => true ] ),
 		] );
 		$this->setService( 'GadgetsRepo', $repo );
 		$optionsLookup = $this->getServiceContainer()->getUserOptionsLookup();
@@ -76,12 +76,12 @@ class GadgetHooksTest extends MediaWikiIntegrationTestCase {
 	public function testPreferences() {
 		$services = $this->getServiceContainer();
 		$repo = new StaticGadgetRepo( [
-			'foo' => new Gadget( [ 'name' => 'foo', 'styles' => 'foo.css' ] ),
-			'bar' => new Gadget( [ 'name' => 'bar', 'styles' => 'bar.css',
+			'foo' => new Gadget( [ 'name' => 'foo', 'pages' => [ 'foo.css' ] ] ),
+			'bar' => new Gadget( [ 'name' => 'bar', 'pages' => [ 'bar.css' ],
 				'category' => 'keep-section1' ] ),
-			'baz' => new Gadget( [ 'name' => 'baz', 'styles' => 'baz.css', 'requiredRights' => [ 'delete' ],
+			'baz' => new Gadget( [ 'name' => 'baz', 'pages' => [ 'baz.css' ], 'requiredRights' => [ 'delete' ],
 				'category' => 'remove-section' ] ),
-			'quux' => new Gadget( [ 'name' => 'quux', 'styles' => 'quux.css', 'requiredRights' => [ 'read' ],
+			'quux' => new Gadget( [ 'name' => 'quux', 'pages' => [ 'quux.css' ], 'requiredRights' => [ 'read' ],
 				'category' => 'keep-section2' ] ),
 		] );
 		$hooks = new GadgetHooks( $repo, $services->getUserOptionsLookup(), null );
diff --git a/tests/phpunit/unit/GadgetTest.php b/tests/phpunit/unit/GadgetTest.php
index 47266e83..ec278d4f 100644
--- a/tests/phpunit/unit/GadgetTest.php
+++ b/tests/phpunit/unit/GadgetTest.php
@@ -38,8 +38,7 @@ class GadgetTest extends MediaWikiUnitTestCase {
 				'requiresES6' => false,
 			],
 			'module' => [
-				'scripts' => [ 'foo.js' ],
-				'styles' => [ 'bar.css' ],
+				'pages' => [ 'foo.js', 'bar.css' ],
 				'datas' => [],
 				'dependencies' => [ 'moment' ],
 				'peers' => [],
@@ -81,12 +80,14 @@ class GadgetTest extends MediaWikiUnitTestCase {
 	 * @covers \MediaWiki\Extension\Gadgets\Gadget
 	 */
 	public function testSimpleCases() {
-		$g = $this->makeGadget( '* foo bar| foo.css|foo.js|foo.bar' );
+		$g = $this->makeGadget( '* foo bar| foo.css|foo.js|foo.json|foo.bar' );
 		$this->assertEquals( 'foo_bar', $g->getName() );
 		$this->assertEquals( 'ext.gadget.foo_bar', Gadget::getModuleName( $g->getName() ) );
 		$this->assertEquals( [ 'MediaWiki:Gadget-foo.js' ], $g->getScripts() );
 		$this->assertEquals( [ 'MediaWiki:Gadget-foo.css' ], $g->getStyles() );
-		$this->assertEquals( [ 'MediaWiki:Gadget-foo.js', 'MediaWiki:Gadget-foo.css' ], $g->getScriptsAndStyles() );
+		$this->assertEquals( [ 'MediaWiki:Gadget-foo.json' ], $g->getJSONs() );
+		$this->assertEquals( [ 'MediaWiki:Gadget-foo.js', 'MediaWiki:Gadget-foo.css', 'MediaWiki:Gadget-foo.json' ],
+			$g->getScriptsAndStyles() );
 		$this->assertEquals( [ 'MediaWiki:Gadget-foo.js' ], $g->getLegacyScripts() );
 		$this->assertFalse( $g->supportsResourceLoader() );
 		$this->assertTrue( $g->hasModule() );