diff --git a/i18n/en.json b/i18n/en.json
index a04be67..88d0b5e 100644
--- a/i18n/en.json
+++ b/i18n/en.json
@@ -91,6 +91,8 @@
 	"math_tip": "Mathematical formula (LaTeX)",
 	"math-tracking-category-error": "Pages with math errors",
 	"math-tracking-category-error-desc": "Pages in this category have errors in the usage of math tags.",
+	"math-tracking-category-mhchem-deprecation": "Pages that use a deprecated format of the chem tags",
+	"math-tracking-category-mhchem-deprecation-desc": "Pages in this category use a deprecated format of the chem tags",
 	"math-tracking-category-render-error": "Pages with math render errors",
 	"math-tracking-category-render-error-desc": "Pages in this category have rendering errors in the math tags.",
 	"math_unknown_error": "unknown error",
diff --git a/i18n/qqq.json b/i18n/qqq.json
index 79fe233..8b2bc04 100644
--- a/i18n/qqq.json
+++ b/i18n/qqq.json
@@ -91,6 +91,8 @@
 	"math_tip": "This is the text that appears when you hover the mouse over the fourth button from the right on the edit toolbar.",
 	"math-tracking-category-error": "Tracking category name.",
 	"math-tracking-category-error-desc": "Tracking category description.",
+	"math-tracking-category-mhchem-deprecation": "Tracking category name.",
+	"math-tracking-category-mhchem-deprecation-desc": "Tracking category description.",
 	"math-tracking-category-render-error": "Tracking category name.",
 	"math-tracking-category-render-error-desc": "Tracking category description.",
 	"math_unknown_error": "Used as error message for unknown texvc error.\n\nThis message follows the message {{msg-mw|Math failure}}.\n{{Identical|Unknown error}}",
diff --git a/src/MathHooks.php b/src/MathHooks.php
index e5c5fda..ca0f4a0 100644
--- a/src/MathHooks.php
+++ b/src/MathHooks.php
@@ -224,22 +224,21 @@ class MathHooks {
 		$checkResult = $renderer->checkTeX();
 
 		if ( $checkResult !== true ) {
-			// Returns the error message and add tracking category
-			$parser->addTrackingCategory( 'math-tracking-category-error' );
+			$renderer->addTrackingCategories( $parser );
 			return $renderer->getLastError();
 		}
 
 		if ( $renderer->render() ) {
 			LoggerFactory::getInstance( 'Math' )->debug( "Rendering successful. Writing output" );
 			$renderedMath = $renderer->getHtmlOutput();
+			$renderer->addTrackingCategories( $parser );
 		} else {
 			LoggerFactory::getInstance( 'Math' )->warning(
 				"Rendering failed. Printing error message." );
 			// Set a short parser cache time (10 minutes) after encountering
 			// render issues, but not syntax issues.
 			$parser->getOutput()->updateCacheExpiry( 600 );
-			// Add a tracking category specialized on render errors.
-			$parser->addTrackingCategory( 'math-tracking-category-render-error' );
+			$renderer->addTrackingCategories( $parser );
 			return $renderer->getLastError();
 		}
 		Hooks::run( 'MathFormulaPostRender',
diff --git a/src/MathMathML.php b/src/MathMathML.php
index 904c164..9a7bd31 100644
--- a/src/MathMathML.php
+++ b/src/MathMathML.php
@@ -52,6 +52,20 @@ class MathMathML extends MathRenderer {
 		}
 	}
 
+	/**
+	 * @inheritDoc
+	 */
+	public function addTrackingCategories( $parser ) {
+		parent::addTrackingCategories( $parser );
+		if ( $this->hasWarnings() ) {
+			foreach ( $this->warnings as $warning ) {
+				if ( isset( $warning->type ) && $warning->type === 'mhchem-deprecation' ) {
+					$parser->addTrackingCategory( 'math-tracking-category-mhchem-deprecation' );
+				}
+			}
+		}
+	}
+
 	public static function batchEvaluate( array $tags ) {
 		$rbis = [];
 		foreach ( $tags as $key => $tag ) {
@@ -120,6 +134,7 @@ class MathMathML extends MathRenderer {
 					$this->mathoidStyle = $rbi->getMathoidStyle();
 					$this->svgPath = $rbi->getFullSvgUrl();
 					$this->pngPath = $rbi->getFullPngUrl();
+					$this->warnings = $rbi->getWarnings();
 				} elseif ( $this->lastError === '' ) {
 					$this->doCheck();
 				}
diff --git a/src/MathRenderer.php b/src/MathRenderer.php
index e40bfe7..60686cb 100644
--- a/src/MathRenderer.php
+++ b/src/MathRenderer.php
@@ -62,6 +62,8 @@ abstract class MathRenderer {
 	protected $inputType = 'tex';
 	/** @var MathRestbaseInterface used for checking */
 	protected $rbi;
+	/** @var array with rendering warnings*/
+	protected $warnings;
 
 	/**
 	 * Constructs a base MathRenderer
@@ -394,6 +396,29 @@ abstract class MathRenderer {
 		$this->rbi->setPurge( $this->isPurge() );
 	}
 
+	public function hasWarnings() {
+		if ( is_array( $this->warnings ) && count( $this->warnings ) ) {
+			return true;
+		}
+
+		return false;
+	}
+
+	/**
+	 * Adds tracking categories to the parser
+	 *
+	 * @param Parser $parser
+	 */
+	public function addTrackingCategories( $parser ) {
+		if ( !$this->checkTeX() ) {
+			$parser->addTrackingCategory( 'math-tracking-category-error' );
+		}
+		if ( $this->lastError ) {
+			// Add a tracking category specialized on render errors.
+			$parser->addTrackingCategory( 'math-tracking-category-render-error' );
+		}
+	}
+
 	/**
 	 * Returns sanitized attributes
 	 *
@@ -593,6 +618,7 @@ abstract class MathRenderer {
 		} else {
 			if ( self::getDisableTexFilter() == 'new' && $this->mode != 'source' ) {
 				if ( $this->readFromDatabase() ) {
+					$this->texSecure = true;
 					return true;
 				}
 			}
diff --git a/src/MathRestbaseInterface.php b/src/MathRestbaseInterface.php
index 0ce23be..e37cd71 100644
--- a/src/MathRestbaseInterface.php
+++ b/src/MathRestbaseInterface.php
@@ -18,6 +18,7 @@ class MathRestbaseInterface {
 	private $error;
 	private $mathoidStyle;
 	private $mml;
+	private $warnings = [];
 	/** @var bool is there a request to purge the existing mathematical content */
 	private $purge = false;
 
@@ -352,6 +353,13 @@ class MathRestbaseInterface {
 		$this->error = (object)[ 'error' => (object)[ 'message' => $msg ] ];
 	}
 
+	/**
+	 * @return array
+	 */
+	public function getWarnings() {
+		return $this->warnings;
+	}
+
 	/**
 	 * @return array
 	 * @throws MWException
@@ -380,6 +388,9 @@ class MathRestbaseInterface {
 			$this->success = $json->success;
 			$this->checkedTex = $json->checked;
 			$this->identifiers = $json->identifiers;
+			if ( isset( $json->warnings ) ) {
+				$this->warnings = $json->warnings;
+			}
 			return true;
 		} else {
 			if ( isset( $json->detail ) && isset( $json->detail->success ) ) {
diff --git a/tests/phpunit/MathMathMLTest.php b/tests/phpunit/MathMathMLTest.php
index 0ec6c28..b39f79e 100644
--- a/tests/phpunit/MathMathMLTest.php
+++ b/tests/phpunit/MathMathMLTest.php
@@ -238,6 +238,28 @@ class MathMathMLTest extends MediaWikiTestCase {
 		$host3 = $method->invoke( $m2, [] );
 		$this->assertEquals( $h2, $host3 );
 	}
+
+	public function testWarning() {
+		$this->setMwGlobals( "wgMathDisableTexFilter", 'always' );
+		$renderer = new MathMathML();
+		$rbi = $this->getMockBuilder( MathRestbaseInterface::class )
+			->setMethods( [ 'getWarnings', 'getSuccess' ] )
+			->setConstructorArgs( [ 'a+b' ] )
+			->getMock();
+		$rbi->method( 'getWarnings' )->willReturn( [ (object)[ 'type' => 'mhchem-deprecation' ] ] );
+		$rbi->method( 'getSuccess' )->willReturn( true );
+		$renderer->setRestbaseInterface( $rbi );
+		$renderer->render();
+		$parser = $this->getMockBuilder( Parser::class )
+			->setMethods( [ 'addTrackingCategory' ] )
+			->disableOriginalConstructor()
+			->getMock();
+		$parser->method( 'addTrackingCategory' )->willReturn( true );
+		$parser->expects( $this->once() )
+			->method( 'addTrackingCategory' )
+			->with( 'math-tracking-category-mhchem-deprecation' );
+		$renderer->addTrackingCategories( $parser );
+	}
 }
 
 /**
diff --git a/tests/phpunit/MathRendererTest.php b/tests/phpunit/MathRendererTest.php
index 2416e65..91d1ce5 100644
--- a/tests/phpunit/MathRendererTest.php
+++ b/tests/phpunit/MathRendererTest.php
@@ -150,7 +150,7 @@ class MathRendererTest extends MediaWikiTestCase {
 					'readFromDatabase',
 					'setTex'
 				] )->setConstructorArgs( [ self::TEXVCCHECK_INPUT ] )->getMock();
-		$renderer->expects( $this->exactly( 2 ) )->method( 'readFromDatabase' )
+		$renderer->expects( $this->exactly( 1 ) )->method( 'readFromDatabase' )
 			->will( $this->returnValue( true ) );
 		$renderer->expects( $this->never() )->method( 'setTex' );