diff --git a/tests/phpunit/tests/ajax/Compression.php b/tests/phpunit/tests/ajax/Compression.php
index 8e42a1e66d..fdb52d3f0b 100644
--- a/tests/phpunit/tests/ajax/Compression.php
+++ b/tests/phpunit/tests/ajax/Compression.php
@@ -25,7 +25,8 @@ class Tests_Ajax_CompressionTest extends WP_Ajax_UnitTestCase {
 		$_GET['test'] = 1;
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'wp-compression-test' );
 	}
 
@@ -118,7 +119,8 @@ class Tests_Ajax_CompressionTest extends WP_Ajax_UnitTestCase {
 		$_SERVER['HTTP_ACCEPT_ENCODING'] = 'unknown';
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'wp-compression-test' );
 	}
 
diff --git a/tests/phpunit/tests/ajax/CustomizeMenus.php b/tests/phpunit/tests/ajax/CustomizeMenus.php
index 3baa07758d..861a4ab6ba 100644
--- a/tests/phpunit/tests/ajax/CustomizeMenus.php
+++ b/tests/phpunit/tests/ajax/CustomizeMenus.php
@@ -53,8 +53,9 @@ class Tests_Ajax_CustomizeMenus extends WP_Ajax_UnitTestCase {
 	function test_ajax_load_available_items_cap_check( $role, $expected_results ) {
 
 		if ( 'administrator' !== $role ) {
-			// If we're not an admin, we should get a wp_die(-1).
-			$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+			// If we're not an admin, we should get a wp_die( -1 ).
+			$this->expectException( 'WPAjaxDieStopException' );
+			$this->expectExceptionMessage( '-1' );
 		}
 
 		wp_set_current_user( self::factory()->user->create( array( 'role' => $role ) ) );
@@ -442,8 +443,9 @@ class Tests_Ajax_CustomizeMenus extends WP_Ajax_UnitTestCase {
 	function test_ajax_search_available_items_caps_check( $role, $expected_results ) {
 
 		if ( 'administrator' !== $role ) {
-			// If we're not an admin, we should get a wp_die(-1).
-			$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+			// If we're not an admin, we should get a wp_die( -1 ).
+			$this->expectException( 'WPAjaxDieStopException' );
+			$this->expectExceptionMessage( '-1' );
 		}
 
 		wp_set_current_user( self::factory()->user->create( array( 'role' => $role ) ) );
diff --git a/tests/phpunit/tests/ajax/DeleteComment.php b/tests/phpunit/tests/ajax/DeleteComment.php
index cc2624872c..70076f001b 100644
--- a/tests/phpunit/tests/ajax/DeleteComment.php
+++ b/tests/phpunit/tests/ajax/DeleteComment.php
@@ -137,7 +137,8 @@ class Tests_Ajax_DeleteComment extends WP_Ajax_UnitTestCase {
 		$_POST['_url']        = admin_url( 'edit-comments.php' );
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'delete-comment' );
 	}
 
@@ -168,7 +169,8 @@ class Tests_Ajax_DeleteComment extends WP_Ajax_UnitTestCase {
 		$_POST['_url']        = admin_url( 'edit-comments.php' );
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'delete-comment' );
 	}
 
diff --git a/tests/phpunit/tests/ajax/DeletePlugin.php b/tests/phpunit/tests/ajax/DeletePlugin.php
index aa22790a42..fb2168c339 100644
--- a/tests/phpunit/tests/ajax/DeletePlugin.php
+++ b/tests/phpunit/tests/ajax/DeletePlugin.php
@@ -12,7 +12,8 @@ require_once ABSPATH . 'wp-admin/includes/ajax-actions.php';
 class Tests_Ajax_Delete_Plugin extends WP_Ajax_UnitTestCase {
 
 	public function test_missing_nonce() {
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'delete-plugin' );
 	}
 
diff --git a/tests/phpunit/tests/ajax/DimComment.php b/tests/phpunit/tests/ajax/DimComment.php
index 51fb2bb9a6..dcf5ba07ab 100644
--- a/tests/phpunit/tests/ajax/DimComment.php
+++ b/tests/phpunit/tests/ajax/DimComment.php
@@ -130,7 +130,8 @@ class Tests_Ajax_DimComment extends WP_Ajax_UnitTestCase {
 		$_POST['_url']        = admin_url( 'edit-comments.php' );
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'dim-comment' );
 	}
 
@@ -158,7 +159,8 @@ class Tests_Ajax_DimComment extends WP_Ajax_UnitTestCase {
 		$_POST['_url']        = admin_url( 'edit-comments.php' );
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'dim-comment' );
 	}
 
diff --git a/tests/phpunit/tests/ajax/EditComment.php b/tests/phpunit/tests/ajax/EditComment.php
index 66ecdae8b4..83f8fee28b 100644
--- a/tests/phpunit/tests/ajax/EditComment.php
+++ b/tests/phpunit/tests/ajax/EditComment.php
@@ -149,7 +149,8 @@ class Tests_Ajax_EditComment extends WP_Ajax_UnitTestCase {
 		$_POST['content']                     = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit.';
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'edit-comment' );
 	}
 
@@ -177,7 +178,8 @@ class Tests_Ajax_EditComment extends WP_Ajax_UnitTestCase {
 		$_POST['content']                     = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit.';
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'get-comments' );
 	}
 
@@ -197,7 +199,8 @@ class Tests_Ajax_EditComment extends WP_Ajax_UnitTestCase {
 		$_POST['content']                     = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit.';
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'edit-comment' );
 	}
 
@@ -225,7 +228,8 @@ class Tests_Ajax_EditComment extends WP_Ajax_UnitTestCase {
 		add_filter( 'wp_update_comment_data', array( $this, '_wp_update_comment_data_filter' ), 10, 3 );
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', 'wp_update_comment_data filter fails for this comment.' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( 'wp_update_comment_data filter fails for this comment.' );
 		$this->_handleAjax( 'edit-comment' );
 	}
 
diff --git a/tests/phpunit/tests/ajax/GetComments.php b/tests/phpunit/tests/ajax/GetComments.php
index b1812ca892..582f5f38ba 100644
--- a/tests/phpunit/tests/ajax/GetComments.php
+++ b/tests/phpunit/tests/ajax/GetComments.php
@@ -90,7 +90,8 @@ class Tests_Ajax_GetComments extends WP_Ajax_UnitTestCase {
 		$_POST['p']           = self::$comment_post->ID;
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'get-comments' );
 	}
 
@@ -110,7 +111,8 @@ class Tests_Ajax_GetComments extends WP_Ajax_UnitTestCase {
 		$_POST['p']           = self::$comment_post->ID;
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'get-comments' );
 	}
 
@@ -130,7 +132,8 @@ class Tests_Ajax_GetComments extends WP_Ajax_UnitTestCase {
 		$_POST['p']           = 'b0rk';
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'get-comments' );
 	}
 
@@ -148,7 +151,8 @@ class Tests_Ajax_GetComments extends WP_Ajax_UnitTestCase {
 		$_POST['p']           = self::$no_comment_post->ID;
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '1' );
 		$this->_handleAjax( 'get-comments' );
 	}
 }
diff --git a/tests/phpunit/tests/ajax/PrivacyErasePersonalData.php b/tests/phpunit/tests/ajax/PrivacyErasePersonalData.php
index 3eb54a6df4..36928f940d 100644
--- a/tests/phpunit/tests/ajax/PrivacyErasePersonalData.php
+++ b/tests/phpunit/tests/ajax/PrivacyErasePersonalData.php
@@ -331,7 +331,8 @@ class Tests_Ajax_PrivacyErasePersonalData extends WP_Ajax_UnitTestCase {
 	 * @since 5.2.0
 	 */
 	public function test_failure_with_invalid_nonce() {
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 
 		$this->_make_ajax_call(
 			array(
diff --git a/tests/phpunit/tests/ajax/PrivacyExportPersonalData.php b/tests/phpunit/tests/ajax/PrivacyExportPersonalData.php
index 6e5c9b8a5b..9ba321e730 100644
--- a/tests/phpunit/tests/ajax/PrivacyExportPersonalData.php
+++ b/tests/phpunit/tests/ajax/PrivacyExportPersonalData.php
@@ -292,7 +292,8 @@ class Tests_Ajax_PrivacyExportPersonalData extends WP_Ajax_UnitTestCase {
 	 * @since 5.2.0
 	 */
 	public function test_failure_with_invalid_nonce() {
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 
 		$this->_make_ajax_call(
 			array(
diff --git a/tests/phpunit/tests/ajax/ReplytoComment.php b/tests/phpunit/tests/ajax/ReplytoComment.php
index 2b160c4597..3e638aa80c 100644
--- a/tests/phpunit/tests/ajax/ReplytoComment.php
+++ b/tests/phpunit/tests/ajax/ReplytoComment.php
@@ -113,7 +113,8 @@ class Tests_Ajax_ReplytoComment extends WP_Ajax_UnitTestCase {
 		$_POST['comment_post_ID']             = self::$comment_post->ID;
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'replyto-comment' );
 	}
 
@@ -142,7 +143,8 @@ class Tests_Ajax_ReplytoComment extends WP_Ajax_UnitTestCase {
 		$_POST['comment_post_ID']             = self::$comment_post->ID;
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'replyto-comment' );
 	}
 
@@ -162,7 +164,8 @@ class Tests_Ajax_ReplytoComment extends WP_Ajax_UnitTestCase {
 		$_POST['comment_post_ID']             = 123456789;
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'replyto-comment' );
 	}
 
@@ -182,7 +185,8 @@ class Tests_Ajax_ReplytoComment extends WP_Ajax_UnitTestCase {
 		$_POST['comment_post_ID']             = self::$draft_post->ID;
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', 'Error: You can’t reply to a comment on a draft post.' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( 'Error: You can’t reply to a comment on a draft post.' );
 		$this->_handleAjax( 'replyto-comment' );
 	}
 
@@ -252,7 +256,8 @@ class Tests_Ajax_ReplytoComment extends WP_Ajax_UnitTestCase {
 		add_filter( 'pre_comment_approved', array( $this, '_pre_comment_approved_filter' ), 10, 2 );
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', 'pre_comment_approved filter fails for new comment' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( 'pre_comment_approved filter fails for new comment.' );
 		$this->_handleAjax( 'replyto-comment' );
 	}
 
@@ -260,6 +265,6 @@ class Tests_Ajax_ReplytoComment extends WP_Ajax_UnitTestCase {
 	 * Blocks comments from being saved on 'pre_comment_approved', by returning WP_Error.
 	 */
 	function _pre_comment_approved_filter( $approved, $commentdata ) {
-		return new WP_Error( 'comment_wrong', 'pre_comment_approved filter fails for new comment', 403 );
+		return new WP_Error( 'comment_wrong', 'pre_comment_approved filter fails for new comment.', 403 );
 	}
 }
diff --git a/tests/phpunit/tests/ajax/TagSearch.php b/tests/phpunit/tests/ajax/TagSearch.php
index 80a327ee93..a92694f46d 100644
--- a/tests/phpunit/tests/ajax/TagSearch.php
+++ b/tests/phpunit/tests/ajax/TagSearch.php
@@ -74,7 +74,8 @@ class Tests_Ajax_TagSearch extends WP_Ajax_UnitTestCase {
 
 		// Make the request.
 		// No output, so we get a stop exception.
-		$this->setExpectedException( 'WPAjaxDieStopException', '' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '' );
 		$this->_handleAjax( 'ajax-tag-search' );
 	}
 
@@ -114,7 +115,8 @@ class Tests_Ajax_TagSearch extends WP_Ajax_UnitTestCase {
 		$_GET['q']   = 'chat';
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'ajax-tag-search' );
 	}
 
@@ -131,7 +133,8 @@ class Tests_Ajax_TagSearch extends WP_Ajax_UnitTestCase {
 		$_GET['q']   = 'chat';
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '0' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '0' );
 		$this->_handleAjax( 'ajax-tag-search' );
 	}
 
@@ -148,7 +151,8 @@ class Tests_Ajax_TagSearch extends WP_Ajax_UnitTestCase {
 		$_GET['q']   = 'chat';
 
 		// Make the request.
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'ajax-tag-search' );
 	}
 
diff --git a/tests/phpunit/tests/ajax/UpdatePlugin.php b/tests/phpunit/tests/ajax/UpdatePlugin.php
index c9690d4f7b..648164c7b2 100644
--- a/tests/phpunit/tests/ajax/UpdatePlugin.php
+++ b/tests/phpunit/tests/ajax/UpdatePlugin.php
@@ -12,7 +12,8 @@ require_once ABSPATH . 'wp-admin/includes/ajax-actions.php';
 class Tests_Ajax_Update_Plugin extends WP_Ajax_UnitTestCase {
 
 	public function test_missing_nonce() {
-		$this->setExpectedException( 'WPAjaxDieStopException', '-1' );
+		$this->expectException( 'WPAjaxDieStopException' );
+		$this->expectExceptionMessage( '-1' );
 		$this->_handleAjax( 'update-plugin' );
 	}