diff --git a/Math.body.php b/Math.body.php
index 54550bb..f4d2481 100644
--- a/Math.body.php
+++ b/Math.body.php
@@ -30,7 +30,7 @@ if ( !function_exists('wfEscapeSingleQuotes') ) {
  * @ingroup Parser
  */
 class MathRenderer {
-	var $mode = MW_MATH_MODERN;
+	var $mode = MW_MATH_PNG;
 	var $tex = '';
 	var $inputhash = '';
 	var $hash = '';
@@ -44,7 +44,13 @@ class MathRenderer {
  	}
 
 	function setOutputMode( $mode ) {
-		$this->mode = $mode;
+		$validModes = array( MW_MATH_PNG, MW_MATH_SOURCE );
+		if ( in_array( $mode, $validModes ) ) {
+			$this->mode = $mode;
+		} else {
+			// Several mixed modes have been phased out.
+			$this->mode = MW_MATH_PNG;
+		}
 	}
 
 	function render() {
diff --git a/Math.hooks.php b/Math.hooks.php
index 4875838..25a7b39 100644
--- a/Math.hooks.php
+++ b/Math.hooks.php
@@ -74,11 +74,7 @@ class MathHooks {
 	private static function getMathNames() {
 		return array(
 			MW_MATH_PNG => 'mw_math_png',
-			MW_MATH_SIMPLE => 'mw_math_simple',
-			MW_MATH_HTML => 'mw_math_html',
-			MW_MATH_SOURCE => 'mw_math_source',
-			MW_MATH_MODERN => 'mw_math_modern',
-			MW_MATH_MATHML => 'mw_math_mathml'
+			MW_MATH_SOURCE => 'mw_math_source'
 		);
 	}
 
diff --git a/Math.php b/Math.php
index a2477b7..bfc4e68 100644
--- a/Math.php
+++ b/Math.php
@@ -31,11 +31,11 @@ $wgExtensionCredits['parserhook'][] = array(
  * Maths constants
  */
 define( 'MW_MATH_PNG',    0 );
-define( 'MW_MATH_SIMPLE', 1 );
-define( 'MW_MATH_HTML',   2 );
+define( 'MW_MATH_SIMPLE', 1 ); /// @deprecated
+define( 'MW_MATH_HTML',   2 ); /// @deprecated
 define( 'MW_MATH_SOURCE', 3 );
-define( 'MW_MATH_MODERN', 4 );
-define( 'MW_MATH_MATHML', 5 );
+define( 'MW_MATH_MODERN', 4 ); /// @deprecated
+define( 'MW_MATH_MATHML', 5 ); /// @deprecated
 /**@}*/
 
 /** For back-compat */
@@ -84,6 +84,7 @@ $wgMathDirectory = false;
 
 ////////// end of config settings.
 
+$wgDefaultUserOptions['math'] = MW_MATH_PNG;
 
 $wgExtensionFunctions[] = 'MathHooks::setup';
 $wgHooks['ParserFirstCallInit'][] = 'MathHooks::onParserFirstCallInit';