diff --git a/WordPress/Tests/DB/RestrictedFunctionsUnitTest.inc b/WordPress/Tests/DB/RestrictedFunctionsUnitTest.inc
index bb976bf8fe..e862f6935c 100644
--- a/WordPress/Tests/DB/RestrictedFunctionsUnitTest.inc
+++ b/WordPress/Tests/DB/RestrictedFunctionsUnitTest.inc
@@ -94,3 +94,11 @@ WP_Date_Query::build_mysql_datetime(); // Ok.
 myFictionFunction(); // Bad.
 myFictional(); // OK.
 Myfictional(); // OK.
+
+/*
+ * Safeguard support for PHP 8.0+ tokenization of namespaced "names".
+ */
+\mysql_connect();
+MyNamespace\mysql_connect();
+\MyNamespace\mysql_connect();
+namespace\mysql_connect(); // The sniff should start flagging this once it can resolve relative namespaces.
diff --git a/WordPress/Tests/DB/RestrictedFunctionsUnitTest.php b/WordPress/Tests/DB/RestrictedFunctionsUnitTest.php
index 73702af626..597dc20d66 100644
--- a/WordPress/Tests/DB/RestrictedFunctionsUnitTest.php
+++ b/WordPress/Tests/DB/RestrictedFunctionsUnitTest.php
@@ -68,54 +68,56 @@ protected function resetGroups() {
 	 */
 	public function getErrorList() {
 		return array(
-			25 => 1,
-			26 => 1,
-			27 => 1,
-			28 => 1,
-			29 => 1,
-			30 => 1,
-			31 => 1,
-			32 => 1,
-			33 => 1,
-
-			36 => 1,
-			37 => 1,
-			38 => 1,
-			39 => 1,
-			40 => 1,
-			41 => 1,
-			42 => 1,
-			43 => 1,
-			44 => 1,
-
-			47 => 1,
-			48 => 1,
-			49 => 1,
-			50 => 1,
-			51 => 1,
-
-			54 => 1,
-			55 => 1,
-			56 => 1,
-			57 => 1,
-
-			60 => 1,
-
-			63 => 1,
-
-			66 => 1,
-			67 => 1,
-			68 => 1,
-			69 => 1,
-			70 => 1,
-			71 => 1,
-			72 => 1,
-			73 => 1,
-			74 => 1,
-			75 => 1,
-			76 => 1,
-
-			94 => 1,
+			25  => 1,
+			26  => 1,
+			27  => 1,
+			28  => 1,
+			29  => 1,
+			30  => 1,
+			31  => 1,
+			32  => 1,
+			33  => 1,
+
+			36  => 1,
+			37  => 1,
+			38  => 1,
+			39  => 1,
+			40  => 1,
+			41  => 1,
+			42  => 1,
+			43  => 1,
+			44  => 1,
+
+			47  => 1,
+			48  => 1,
+			49  => 1,
+			50  => 1,
+			51  => 1,
+
+			54  => 1,
+			55  => 1,
+			56  => 1,
+			57  => 1,
+
+			60  => 1,
+
+			63  => 1,
+
+			66  => 1,
+			67  => 1,
+			68  => 1,
+			69  => 1,
+			70  => 1,
+			71  => 1,
+			72  => 1,
+			73  => 1,
+			74  => 1,
+			75  => 1,
+			76  => 1,
+
+			94  => 1,
+
+			101 => 1,
 		);
 	}
 
diff --git a/WordPress/Tests/DateTime/RestrictedFunctionsUnitTest.inc b/WordPress/Tests/DateTime/RestrictedFunctionsUnitTest.inc
index 25227b5178..4c3a6d11bc 100644
--- a/WordPress/Tests/DateTime/RestrictedFunctionsUnitTest.inc
+++ b/WordPress/Tests/DateTime/RestrictedFunctionsUnitTest.inc
@@ -7,3 +7,11 @@ $date->setTimezone( new DateTimeZone( 'America/Toronto' ) ); // Yay!
 
 $post_data['post_title'] = sprintf( __( 'Draft created on %1$s at %2$s' ), date( __( 'F j, Y' ), $now ), date( __( 'g:i a' ), $now ) ); // Error.
 $post_data['post_title'] = sprintf( __( 'Draft created on %1$s at %2$s' ), gmdate( __( 'F j, Y' ), $now ), gmdate( __( 'g:i a' ), $now ) ); // OK.
+
+/*
+ * Safeguard support for PHP 8.0+ tokenization of namespaced "names".
+ */
+\date_default_timezone_set( 'Foo/Bar' );
+MyNamespace\date_default_timezone_set( 'Foo/Bar' );
+\MyNamespace\date_default_timezone_set( 'Foo/Bar' );
+namespace\date_default_timezone_set( 'Foo/Bar' ); // The sniff should start flagging this once it can resolve relative namespaces.
diff --git a/WordPress/Tests/DateTime/RestrictedFunctionsUnitTest.php b/WordPress/Tests/DateTime/RestrictedFunctionsUnitTest.php
index f5e160bc62..a2f29c2364 100644
--- a/WordPress/Tests/DateTime/RestrictedFunctionsUnitTest.php
+++ b/WordPress/Tests/DateTime/RestrictedFunctionsUnitTest.php
@@ -27,8 +27,9 @@ final class RestrictedFunctionsUnitTest extends AbstractSniffUnitTest {
 	 */
 	public function getErrorList() {
 		return array(
-			3 => 1,
-			8 => 2,
+			3  => 1,
+			8  => 2,
+			14 => 1,
 		);
 	}
 
diff --git a/WordPress/Tests/PHP/DevelopmentFunctionsUnitTest.inc b/WordPress/Tests/PHP/DevelopmentFunctionsUnitTest.inc
index b07e7a8ce6..fec3eaa978 100644
--- a/WordPress/Tests/PHP/DevelopmentFunctionsUnitTest.inc
+++ b/WordPress/Tests/PHP/DevelopmentFunctionsUnitTest.inc
@@ -35,5 +35,11 @@ phpinfo(); // Error.
 
 Wrapper_Class::var_dump(); // OK, not the native PHP function.
 $wrapper ->var_dump(); // OK, not the native PHP function.
-namespace\var_dump(); // OK as long as the file is namespaced.
-MyNamespace\var_dump(); // OK, namespaced function.
+
+/*
+ * Safeguard support for PHP 8.0+ tokenization of namespaced "names".
+ */
+\var_dump( $value );
+MyNamespace\var_dump( $value );
+\MyNamespace\var_dump( $value );
+namespace\var_dump( $value ); // The sniff should start flagging this once it can resolve relative namespaces.
diff --git a/WordPress/Tests/PHP/DevelopmentFunctionsUnitTest.php b/WordPress/Tests/PHP/DevelopmentFunctionsUnitTest.php
index 8be090a5bf..f3e953545c 100644
--- a/WordPress/Tests/PHP/DevelopmentFunctionsUnitTest.php
+++ b/WordPress/Tests/PHP/DevelopmentFunctionsUnitTest.php
@@ -52,6 +52,7 @@ public function getWarningList() {
 			24 => 1,
 			33 => 1,
 			34 => 1,
+			42 => 1,
 		);
 	}
 }
diff --git a/WordPress/Tests/PHP/DiscouragedPHPFunctionsUnitTest.inc b/WordPress/Tests/PHP/DiscouragedPHPFunctionsUnitTest.inc
index 9a17c8a6d8..7049336d73 100644
--- a/WordPress/Tests/PHP/DiscouragedPHPFunctionsUnitTest.inc
+++ b/WordPress/Tests/PHP/DiscouragedPHPFunctionsUnitTest.inc
@@ -41,3 +41,11 @@ $handle = popen( '/bin/ls', 'r' );
 // Issue #898.
 class System {}
 class Serialize {}
+
+/*
+ * Safeguard support for PHP 8.0+ tokenization of namespaced "names".
+ */
+\serialize( $value );
+MyNamespace\serialize( $value );
+\MyNamespace\serialize( $value );
+namespace\serialize( $value ); // The sniff should start flagging this once it can resolve relative namespaces.
diff --git a/WordPress/Tests/PHP/DiscouragedPHPFunctionsUnitTest.php b/WordPress/Tests/PHP/DiscouragedPHPFunctionsUnitTest.php
index ee28c4fe42..5084e05911 100644
--- a/WordPress/Tests/PHP/DiscouragedPHPFunctionsUnitTest.php
+++ b/WordPress/Tests/PHP/DiscouragedPHPFunctionsUnitTest.php
@@ -60,6 +60,7 @@ public function getWarningList() {
 			37 => 1,
 			38 => 1,
 			39 => 1,
+			48 => 1,
 		);
 	}
 }
diff --git a/WordPress/Tests/PHP/DontExtractUnitTest.inc b/WordPress/Tests/PHP/DontExtractUnitTest.inc
index 9ed5c3d2b2..ea5b9dfcec 100644
--- a/WordPress/Tests/PHP/DontExtractUnitTest.inc
+++ b/WordPress/Tests/PHP/DontExtractUnitTest.inc
@@ -7,3 +7,11 @@ my_extract(); // Ok.
 My_Object::extract(); // Ok.
 $this->extract(); // Ok.
 $my_object->extract(); // Ok.
+
+/*
+ * Safeguard support for PHP 8.0+ tokenization of namespaced "names".
+ */
+\extract( array( 'a' => 1 ) );
+MyNamespace\extract( array( 'a' => 1 ) );
+\MyNamespace\extract( array( 'a' => 1 ) );
+namespace\extract( array( 'a' => 1 ) ); // The sniff should start flagging this once it can resolve relative namespaces.
diff --git a/WordPress/Tests/PHP/DontExtractUnitTest.php b/WordPress/Tests/PHP/DontExtractUnitTest.php
index 3efee7c9a8..f9a1df7494 100644
--- a/WordPress/Tests/PHP/DontExtractUnitTest.php
+++ b/WordPress/Tests/PHP/DontExtractUnitTest.php
@@ -29,7 +29,8 @@ final class DontExtractUnitTest extends AbstractSniffUnitTest {
 	 */
 	public function getErrorList() {
 		return array(
-			3 => 1,
+			3  => 1,
+			14 => 1,
 		);
 	}
 
diff --git a/WordPress/Tests/PHP/POSIXFunctionsUnitTest.inc b/WordPress/Tests/PHP/POSIXFunctionsUnitTest.inc
index 785779e02b..34e0de6722 100644
--- a/WordPress/Tests/PHP/POSIXFunctionsUnitTest.inc
+++ b/WordPress/Tests/PHP/POSIXFunctionsUnitTest.inc
@@ -24,3 +24,11 @@ list( $year, $month, $day ) = split( ':', $date ); // Bad, split has been deprec
 $title_parts = spliti( ' ', get_the_title(), 4 ); // Bad, spliti also deprecated. Use preg_split instead.
 
 sql_regcase( 'Foo - bar.'); // Bad. Deprecated.
+
+/*
+ * Safeguard support for PHP 8.0+ tokenization of namespaced "names".
+ */
+\split( ':', $date );
+MyNamespace\split( ':', $date );
+\MyNamespace\split( ':', $date );
+namespace\split( ':', $date ); // The sniff should start flagging this once it can resolve relative namespaces.
diff --git a/WordPress/Tests/PHP/POSIXFunctionsUnitTest.php b/WordPress/Tests/PHP/POSIXFunctionsUnitTest.php
index 7dbfcd6100..d4086c3e49 100644
--- a/WordPress/Tests/PHP/POSIXFunctionsUnitTest.php
+++ b/WordPress/Tests/PHP/POSIXFunctionsUnitTest.php
@@ -35,6 +35,7 @@ public function getErrorList() {
 			22 => 1,
 			24 => 1,
 			26 => 1,
+			31 => 1,
 		);
 	}
 
diff --git a/WordPress/Tests/PHP/RestrictedPHPFunctionsUnitTest.inc b/WordPress/Tests/PHP/RestrictedPHPFunctionsUnitTest.inc
index 84dbd1d7b3..3edf622b1a 100644
--- a/WordPress/Tests/PHP/RestrictedPHPFunctionsUnitTest.inc
+++ b/WordPress/Tests/PHP/RestrictedPHPFunctionsUnitTest.inc
@@ -3,3 +3,11 @@
 add_action( 'widgets_init', create_function( '', // Error.
 	'return register_widget( "time_more_on_time_widget" );'
 ) );
+
+/*
+ * Safeguard support for PHP 8.0+ tokenization of namespaced "names".
+ */
+\create_function('', 'return;');
+MyNamespace\create_function('', 'return;');
+\MyNamespace\create_function('', 'return;');
+namespace\create_function('', 'return;'); // The sniff should start flagging this once it can resolve relative namespaces.
diff --git a/WordPress/Tests/PHP/RestrictedPHPFunctionsUnitTest.php b/WordPress/Tests/PHP/RestrictedPHPFunctionsUnitTest.php
index d930ba4329..5cfa75ae51 100644
--- a/WordPress/Tests/PHP/RestrictedPHPFunctionsUnitTest.php
+++ b/WordPress/Tests/PHP/RestrictedPHPFunctionsUnitTest.php
@@ -27,7 +27,8 @@ final class RestrictedPHPFunctionsUnitTest extends AbstractSniffUnitTest {
 	 */
 	public function getErrorList() {
 		return array(
-			3 => 1,
+			3  => 1,
+			10 => 1,
 		);
 	}
 
diff --git a/WordPress/Tests/Security/SafeRedirectUnitTest.inc b/WordPress/Tests/Security/SafeRedirectUnitTest.inc
index 690fbe70f0..bbdc66b314 100644
--- a/WordPress/Tests/Security/SafeRedirectUnitTest.inc
+++ b/WordPress/Tests/Security/SafeRedirectUnitTest.inc
@@ -2,3 +2,11 @@
 
 wp_redirect( $location ); // Warning.
 wp_safe_redirect( $location ); // OK.
+
+/*
+ * Safeguard support for PHP 8.0+ tokenization of namespaced "names".
+ */
+\wp_redirect( $location );
+MyNamespace\wp_redirect( $location );
+\MyNamespace\wp_redirect( $location );
+namespace\wp_redirect( $location ); // The sniff should start flagging this once it can resolve relative namespaces.
diff --git a/WordPress/Tests/Security/SafeRedirectUnitTest.php b/WordPress/Tests/Security/SafeRedirectUnitTest.php
index b62e6f86c8..358cdcfdd1 100644
--- a/WordPress/Tests/Security/SafeRedirectUnitTest.php
+++ b/WordPress/Tests/Security/SafeRedirectUnitTest.php
@@ -37,6 +37,7 @@ public function getErrorList() {
 	public function getWarningList() {
 		return array(
 			3 => 1,
+			9 => 1,
 		);
 	}
 }
diff --git a/WordPress/Tests/WP/AlternativeFunctionsUnitTest.inc b/WordPress/Tests/WP/AlternativeFunctionsUnitTest.inc
index a88e5638a9..3336dd0b18 100644
--- a/WordPress/Tests/WP/AlternativeFunctionsUnitTest.inc
+++ b/WordPress/Tests/WP/AlternativeFunctionsUnitTest.inc
@@ -147,3 +147,11 @@ file_get_contents(
 	// Not using plugin_dir_path() for reasons.
 	$url
 ); // Warning.
+
+/*
+ * Safeguard support for PHP 8.0+ tokenization of namespaced "names".
+ */
+\curl_init();
+MyNamespace\curl_init();
+\MyNamespace\curl_init();
+namespace\curl_init(); // The sniff should start flagging this once it can resolve relative namespaces.
diff --git a/WordPress/Tests/WP/AlternativeFunctionsUnitTest.php b/WordPress/Tests/WP/AlternativeFunctionsUnitTest.php
index b0f1bf96aa..e660886adb 100644
--- a/WordPress/Tests/WP/AlternativeFunctionsUnitTest.php
+++ b/WordPress/Tests/WP/AlternativeFunctionsUnitTest.php
@@ -89,6 +89,7 @@ public function getWarningList() {
 			131 => 1,
 			142 => 1,
 			146 => 1,
+			154 => 1,
 		);
 	}
 }
diff --git a/WordPress/Tests/WP/DeprecatedFunctionsUnitTest.inc b/WordPress/Tests/WP/DeprecatedFunctionsUnitTest.1.inc
similarity index 100%
rename from WordPress/Tests/WP/DeprecatedFunctionsUnitTest.inc
rename to WordPress/Tests/WP/DeprecatedFunctionsUnitTest.1.inc
diff --git a/WordPress/Tests/WP/DeprecatedFunctionsUnitTest.2.inc b/WordPress/Tests/WP/DeprecatedFunctionsUnitTest.2.inc
new file mode 100644
index 0000000000..936b2b94f4
--- /dev/null
+++ b/WordPress/Tests/WP/DeprecatedFunctionsUnitTest.2.inc
@@ -0,0 +1,9 @@
+<?php
+
+/*
+ * Safeguard support for PHP 8.0+ tokenization of namespaced "names".
+ */
+\the_category_ID();
+MyNamespace\the_category_ID();
+\MyNamespace\the_category_ID();
+namespace\the_category_ID(); // The sniff should start flagging this once it can resolve relative namespaces.
diff --git a/WordPress/Tests/WP/DeprecatedFunctionsUnitTest.php b/WordPress/Tests/WP/DeprecatedFunctionsUnitTest.php
index ffecae7e33..fb53e37231 100644
--- a/WordPress/Tests/WP/DeprecatedFunctionsUnitTest.php
+++ b/WordPress/Tests/WP/DeprecatedFunctionsUnitTest.php
@@ -24,85 +24,106 @@ final class DeprecatedFunctionsUnitTest extends AbstractSniffUnitTest {
 	/**
 	 * Returns the lines where errors should occur.
 	 *
+	 * @param string $testFile The test file to check for errors.
+	 *
 	 * @return array<int, int> Key is the line number, value is the number of expected errors.
 	 */
-	public function getErrorList() {
-		$start_line = 8;
-		$end_line   = 420;
-		$errors     = array_fill( $start_line, ( ( $end_line - $start_line ) + 1 ), 1 );
+	public function getErrorList( $testFile = '' ) {
+		switch ( $testFile ) {
+			case 'DeprecatedFunctionsUnitTest.1.inc':
+				$start_line = 8;
+				$end_line   = 420;
+				$errors     = array_fill( $start_line, ( ( $end_line - $start_line ) + 1 ), 1 );
+
+				// Unset the lines related to version comments.
+				unset(
+					$errors[10],
+					$errors[12],
+					$errors[14],
+					$errors[16],
+					$errors[29],
+					$errors[55],
+					$errors[57],
+					$errors[59],
+					$errors[73],
+					$errors[76],
+					$errors[80],
+					$errors[102], // Undeprecated function.
+					$errors[118],
+					$errors[125],
+					$errors[162],
+					$errors[175],
+					$errors[179],
+					$errors[211],
+					$errors[234],
+					$errors[252],
+					$errors[256],
+					$errors[263],
+					$errors[275],
+					$errors[282],
+					$errors[286],
+					$errors[291],
+					$errors[296],
+					$errors[304],
+					$errors[311],
+					$errors[319],
+					$errors[323],
+					$errors[330],
+					$errors[332],
+					$errors[337],
+					$errors[340],
+					$errors[344],
+					$errors[346],
+					$errors[353],
+					$errors[357],
+					$errors[359],
+					$errors[361],
+					$errors[363],
+					$errors[369],
+					$errors[371],
+					$errors[373],
+					$errors[383],
+					$errors[386],
+					$errors[410]
+				);
+
+				return $errors;
 
-		// Unset the lines related to version comments.
-		unset(
-			$errors[10],
-			$errors[12],
-			$errors[14],
-			$errors[16],
-			$errors[29],
-			$errors[55],
-			$errors[57],
-			$errors[59],
-			$errors[73],
-			$errors[76],
-			$errors[80],
-			$errors[102], // Undeprecated function.
-			$errors[118],
-			$errors[125],
-			$errors[162],
-			$errors[175],
-			$errors[179],
-			$errors[211],
-			$errors[234],
-			$errors[252],
-			$errors[256],
-			$errors[263],
-			$errors[275],
-			$errors[282],
-			$errors[286],
-			$errors[291],
-			$errors[296],
-			$errors[304],
-			$errors[311],
-			$errors[319],
-			$errors[323],
-			$errors[330],
-			$errors[332],
-			$errors[337],
-			$errors[340],
-			$errors[344],
-			$errors[346],
-			$errors[353],
-			$errors[357],
-			$errors[359],
-			$errors[361],
-			$errors[363],
-			$errors[369],
-			$errors[371],
-			$errors[373],
-			$errors[383],
-			$errors[386],
-			$errors[410]
-		);
+			case 'DeprecatedFunctionsUnitTest.2.inc':
+				return array(
+					6 => 1,
+				);
 
-		return $errors;
+			default:
+				return array();
+		}
 	}
 
 	/**
 	 * Returns the lines where warnings should occur.
 	 *
+	 * @param string $testFile The test file to check for warnings.
+	 *
 	 * @return array<int, int> Key is the line number, value is the number of expected warnings.
 	 */
-	public function getWarningList() {
-		$start_line = 426;
-		$end_line   = 443;
-		$warnings   = array_fill( $start_line, ( ( $end_line - $start_line ) + 1 ), 1 );
+	public function getWarningList( $testFile = '' ) {
+		switch ( $testFile ) {
+			case 'DeprecatedFunctionsUnitTest.1.inc':
+				$start_line = 426;
+				$end_line   = 443;
+				$warnings   = array_fill( $start_line, ( ( $end_line - $start_line ) + 1 ), 1 );
+
+				// Unset the lines related to version comments.
+				unset(
+					$warnings[429],
+					$warnings[432],
+					$warnings[442]
+				);
 
-		// Unset the lines related to version comments.
-		unset(
-			$warnings[429],
-			$warnings[432],
-			$warnings[442]
-		);
+				return $warnings;
 
-		return $warnings;
+			default:
+				return array();
+		}
 	}
 }
diff --git a/WordPress/Tests/WP/DiscouragedFunctionsUnitTest.inc b/WordPress/Tests/WP/DiscouragedFunctionsUnitTest.inc
index 5e952933d2..66a33f4984 100644
--- a/WordPress/Tests/WP/DiscouragedFunctionsUnitTest.inc
+++ b/WordPress/Tests/WP/DiscouragedFunctionsUnitTest.inc
@@ -14,8 +14,8 @@ $obj?->query_posts(); // OK, not the global function.
 
 // Ensure the sniff doesn't act on namespaced calls.
 MyNamespace\query_posts(); // OK, not the global function.
+\MyNamespace\query_posts(); // OK, not the global function.
 namespace\query_posts(); // OK, not the global function.
-
 // ... but does act on fully qualified function calls.
 \query_posts(); // Warning.