diff --git a/test/data/testrunner.js b/test/data/testrunner.js
index c4fa5d378..816b271a6 100644
--- a/test/data/testrunner.js
+++ b/test/data/testrunner.js
@@ -21,74 +21,6 @@ QUnit.config.testTimeout = 60e3; // 1 minute
 // Enforce an "expect" argument or expect() call in all test bodies.
 QUnit.config.requireExpects = true;
 
-/**
- * @param {jQuery|HTMLElement|Object|Array} elems Target (or array of targets) for jQuery.data.
- * @param {string} key
- */
-QUnit.assert.expectJqData = function( env, elems, key ) {
-	var i, elem, expando;
-
-	// As of jQuery 2.0, there will be no "cache"-data is
-	// stored and managed completely below the API surface
-	if ( jQuery.cache ) {
-		env.checkJqData = true;
-
-		if ( elems.jquery && elems.toArray ) {
-			elems = elems.toArray();
-		}
-		if ( !Array.isArray( elems ) ) {
-			elems = [ elems ];
-		}
-
-		for ( i = 0; i < elems.length; i++ ) {
-			elem = elems[ i ];
-
-			// jQuery.data only stores data for nodes in jQuery.cache,
-			// for other data targets the data is stored in the object itself,
-			// in that case we can't test that target for memory leaks.
-			// But we don't have to since in that case the data will/must will
-			// be available as long as the object is not garbage collected by
-			// the js engine, and when it is, the data will be removed with it.
-			if ( !elem.nodeType ) {
-
-				// Fixes false positives for dataTests(window), dataTests({}).
-				continue;
-			}
-
-			expando = elem[ jQuery.expando ];
-
-			if ( expando === undefined ) {
-
-				// In this case the element exists fine, but
-				// jQuery.data (or internal data) was never (in)directly
-				// called.
-				// Since this method was called it means some data was
-				// expected to be found, but since there is nothing, fail early
-				// (instead of in teardown).
-				this.notStrictEqual(
-					expando,
-					undefined,
-					"Target for expectJqData must have an expando, " +
-						"for else there can be no data to expect."
-				);
-			} else {
-				if ( expectedDataKeys[ expando ] ) {
-					expectedDataKeys[ expando ].push( key );
-				} else {
-					expectedDataKeys[ expando ] = [ key ];
-				}
-			}
-		}
-	}
-
-};
-QUnit.config.urlConfig.push( {
-	id: "jqdata",
-	label: "Always check jQuery.data",
-	tooltip: "Trigger QUnit.expectJqData detection for all tests " +
-		"instead of just the ones that call it"
-} );
-
 /**
  * Ensures that tests have cleaned up properly after themselves. Should be passed as the
  * teardown function on all modules' lifecycle object.
@@ -97,30 +29,6 @@ window.moduleTeardown = function( assert ) {
 	var i, expectedKeys, actualKeys,
 		cacheLength = 0;
 
-	// Only look for jQuery data problems if this test actually
-	// provided some information to compare against.
-	if ( QUnit.urlParams.jqdata || this.checkJqData ) {
-		for ( i in jQuery.cache ) {
-			expectedKeys = expectedDataKeys[ i ];
-			actualKeys = jQuery.cache[ i ] ? Object.keys( jQuery.cache[ i ] ) : jQuery.cache[ i ];
-			if ( !QUnit.equiv( expectedKeys, actualKeys ) ) {
-				assert.deepEqual( actualKeys, expectedKeys, "Expected keys exist in jQuery.cache" );
-			}
-			delete jQuery.cache[ i ];
-			delete expectedDataKeys[ i ];
-		}
-
-		// In case it was removed from cache before (or never there in the first place)
-		for ( i in expectedDataKeys ) {
-			assert.deepEqual(
-				expectedDataKeys[ i ],
-				undefined,
-				"No unexpected keys were left in jQuery.cache (#" + i + ")"
-			);
-			delete expectedDataKeys[ i ];
-		}
-	}
-
 	// Reset data register
 	expectedDataKeys = {};
 
diff --git a/test/unit/attributes.js b/test/unit/attributes.js
index 41bdadb18..386aadaf3 100644
--- a/test/unit/attributes.js
+++ b/test/unit/attributes.js
@@ -1411,10 +1411,6 @@ var testToggleClass = function( valueObj, assert ) {
 	e.toggleClass( false );
 	e.toggleClass();
 	assert.ok( e.is( ".testD.testE" ), "Assert class present (restored from data)" );
-
-	// Cleanup
-	e.removeClass( "testD" );
-	assert.expectJqData( this, e[ 0 ], "__className__" );
 };
 
 QUnit.test( "toggleClass(String|boolean|undefined[, boolean])", function( assert ) {
diff --git a/test/unit/data.js b/test/unit/data.js
index 7e019a4ce..154ea5eeb 100644
--- a/test/unit/data.js
+++ b/test/unit/data.js
@@ -132,11 +132,6 @@ QUnit.test( "jQuery.data(div)", function( assert ) {
 	var div = document.createElement( "div" );
 
 	dataTests( div, assert );
-
-	// We stored one key in the private data
-	// assert that nothing else was put in there, and that that
-	// one stayed there.
-	assert.expectJqData( this, div, "foo" );
 } );
 
 QUnit.test( "jQuery.data({})", function( assert ) {
@@ -159,8 +154,6 @@ QUnit.test( "jQuery.data(document)", function( assert ) {
 	assert.expect( 25 );
 
 	dataTests( document, assert );
-
-	assert.expectJqData( this, document, "foo" );
 } );
 
 QUnit.test( "jQuery.data(<embed>)", function( assert ) {
diff --git a/test/unit/effects.js b/test/unit/effects.js
index 13190dc5b..278545ab9 100644
--- a/test/unit/effects.js
+++ b/test/unit/effects.js
@@ -90,9 +90,6 @@ QUnit.test( "show()", function( assert ) {
 		assert.ok( pass, "Show with " + name + " does not call animate callback" );
 	} );
 
-	// Tolerate data from show()/hide()
-	assert.expectJqData( this, div, "olddisplay" );
-
 	jQuery(
 		"<div id='show-tests'>" +
 		"<div><p><a href='#'></a></p><code></code><pre></pre><span></span></div>" +
@@ -217,8 +214,6 @@ supportjQuery.each( hideOptions, function( type, setup ) {
 		} );
 
 		clock.tick( 300 );
-
-		assert.expectJqData( this, $span, "olddisplay" );
 	} );
 
 	// Support: IE 11+, Edge 12 - 18+
@@ -251,8 +246,6 @@ supportjQuery.each( hideOptions, function( type, setup ) {
 		} );
 
 		clock.tick( 300 );
-
-		assert.expectJqData( this, $shadowChild, "olddisplay" );
 	} );
 } );
 
@@ -1161,9 +1154,6 @@ QUnit.test( "interrupt toggle", function( assert ) {
 
 			// Save original property value for comparison
 			jQuery.data( this, "startVal", jQuery( this ).css( prop ) );
-
-			// Expect olddisplay data from our .hide() call below
-			assert.expectJqData( env, this, "olddisplay" );
 		} );
 
 		// Interrupt a hiding toggle
@@ -1613,8 +1603,6 @@ QUnit.test( "animate should set display for disconnected nodes", function( asser
 	assert.strictEqual( $divInline.show()[ 0 ].style.display, "inline",
 		"show() should not change display if it already set" );
 
-	assert.expectJqData( env, $divNone[ 0 ], "olddisplay" );
-
 	jQuery.each( showMethods, function( name, opt ) {
 		jQuery.fn[ name ].apply( jQuery( "<div/>" ), opt.concat( [ function() {
 			assert.strictEqual( jQuery( this ).css( "display" ), nullParentDisplay,