diff --git a/includes/libs/objectcache/APCUBagOStuff.php b/includes/libs/objectcache/APCUBagOStuff.php
index becfb850e39..6f2d8db93c4 100644
--- a/includes/libs/objectcache/APCUBagOStuff.php
+++ b/includes/libs/objectcache/APCUBagOStuff.php
@@ -62,11 +62,12 @@ class APCUBagOStuff extends MediumSpecificBagOStuff {
 	}
 
 	protected function doGet( $key, $flags = 0, &$casToken = null ) {
+		$getToken = ( $casToken === self::PASS_BY_REF );
 		$casToken = null;
 
 		$blob = apcu_fetch( $key . self::KEY_SUFFIX );
 		$value = $this->nativeSerialize ? $blob : $this->unserialize( $blob );
-		if ( $value !== false ) {
+		if ( $getToken && $value !== false ) {
 			$casToken = $blob; // don't bother hashing this
 		}
 
diff --git a/includes/libs/objectcache/HashBagOStuff.php b/includes/libs/objectcache/HashBagOStuff.php
index d8e73b2fc8e..136d4622273 100644
--- a/includes/libs/objectcache/HashBagOStuff.php
+++ b/includes/libs/objectcache/HashBagOStuff.php
@@ -65,6 +65,7 @@ class HashBagOStuff extends MediumSpecificBagOStuff {
 	}
 
 	protected function doGet( $key, $flags = 0, &$casToken = null ) {
+		$getToken = ( $casToken === self::PASS_BY_REF );
 		$casToken = null;
 
 		if ( !$this->hasKey( $key ) || $this->expire( $key ) ) {
@@ -76,7 +77,9 @@ class HashBagOStuff extends MediumSpecificBagOStuff {
 		unset( $this->bag[$key] );
 		$this->bag[$key] = $temp;
 
-		$casToken = $this->bag[$key][self::KEY_CAS];
+		if ( $getToken ) {
+			$casToken = $this->bag[$key][self::KEY_CAS];
+		}
 
 		return $this->bag[$key][self::KEY_VAL];
 	}
diff --git a/includes/libs/objectcache/MediumSpecificBagOStuff.php b/includes/libs/objectcache/MediumSpecificBagOStuff.php
index c0146830c82..7ea6fca3e8a 100644
--- a/includes/libs/objectcache/MediumSpecificBagOStuff.php
+++ b/includes/libs/objectcache/MediumSpecificBagOStuff.php
@@ -61,6 +61,9 @@ abstract class MediumSpecificBagOStuff extends BagOStuff {
 	/** @var string Component to use for key construction of blob segment keys */
 	private const SEGMENT_COMPONENT = 'segment';
 
+	/** @var int Idiom for doGet() to return extra information by reference */
+	protected const PASS_BY_REF = -1;
+
 	/**
 	 * @see BagOStuff::__construct()
 	 * Additional $params options include:
@@ -151,7 +154,7 @@ abstract class MediumSpecificBagOStuff extends BagOStuff {
 	/**
 	 * @param string $key
 	 * @param int $flags Bitfield of BagOStuff::READ_* constants [optional]
-	 * @param mixed|null &$casToken Token to use for check-and-set comparisons
+	 * @param mixed|null &$casToken cas() token if MediumSpecificBagOStuff::PASS_BY_REF [returned]
 	 * @return mixed Returns false on failure or if the item does not exist
 	 */
 	abstract protected function doGet( $key, $flags = 0, &$casToken = null );
@@ -275,7 +278,7 @@ abstract class MediumSpecificBagOStuff extends BagOStuff {
 	final protected function mergeViaCas( $key, callable $callback, $exptime, $attempts, $flags ) {
 		$attemptsLeft = $attempts;
 		do {
-			$token = null; // passed by reference
+			$token = self::PASS_BY_REF; // passed by reference
 			// Get the old value and CAS token from cache
 			$this->clearLastError();
 			$currentValue = $this->resolveSegments(
@@ -366,7 +369,7 @@ abstract class MediumSpecificBagOStuff extends BagOStuff {
 			return false; // non-blocking
 		}
 
-		$curCasToken = null; // passed by reference
+		$curCasToken = self::PASS_BY_REF; // passed by reference
 		$this->clearLastError();
 		$this->doGet( $key, self::READ_LATEST, $curCasToken );
 		if ( is_object( $curCasToken ) ) {
diff --git a/includes/libs/objectcache/MemcachedPeclBagOStuff.php b/includes/libs/objectcache/MemcachedPeclBagOStuff.php
index b7ae826d103..b0012883227 100644
--- a/includes/libs/objectcache/MemcachedPeclBagOStuff.php
+++ b/includes/libs/objectcache/MemcachedPeclBagOStuff.php
@@ -178,10 +178,14 @@ class MemcachedPeclBagOStuff extends MemcachedBagOStuff {
 	}
 
 	protected function doGet( $key, $flags = 0, &$casToken = null ) {
+		$getToken = ( $casToken === self::PASS_BY_REF );
+		$casToken = null;
+
 		$this->debug( "get($key)" );
 
 		$client = $this->acquireSyncClient();
-		if ( defined( Memcached::class . '::GET_EXTENDED' ) ) { // v3.0.0
+		// T257003: only require "gets" (instead of "get") when a CAS token is needed
+		if ( $getToken ) {
 			/** @noinspection PhpUndefinedClassConstantInspection */
 			$flags = Memcached::GET_EXTENDED;
 			$res = $client->get( $this->validateKeyEncoding( $key ), null, $flags );
@@ -193,7 +197,7 @@ class MemcachedPeclBagOStuff extends MemcachedBagOStuff {
 				$casToken = null;
 			}
 		} else {
-			$result = $client->get( $this->validateKeyEncoding( $key ), null, $casToken );
+			$result = $client->get( $this->validateKeyEncoding( $key ) );
 		}
 
 		return $this->checkResult( $key, $result );
@@ -327,7 +331,9 @@ class MemcachedPeclBagOStuff extends MemcachedBagOStuff {
 			$this->validateKeyEncoding( $key );
 		}
 
-		// The PECL implementation uses "gets" which works as well as a pipeline
+		// The PECL implementation uses multi-key "get"/"gets"; no need to pipeline.
+		// T257003: avoid Memcached::GET_EXTENDED; no tokens are needed and that requires "gets"
+		// https://github.com/libmemcached/libmemcached/blob/eda2becbec24363f56115fa5d16d38a2d1f54775/libmemcached/get.cc#L272
 		$result = $this->acquireSyncClient()->getMulti( $keys ) ?: [];
 
 		return $this->checkResult( false, $result );
diff --git a/includes/libs/objectcache/MemcachedPhpBagOStuff.php b/includes/libs/objectcache/MemcachedPhpBagOStuff.php
index 53a205048b8..0c88a20b7e7 100644
--- a/includes/libs/objectcache/MemcachedPhpBagOStuff.php
+++ b/includes/libs/objectcache/MemcachedPhpBagOStuff.php
@@ -59,9 +59,12 @@ class MemcachedPhpBagOStuff extends MemcachedBagOStuff {
 	}
 
 	protected function doGet( $key, $flags = 0, &$casToken = null ) {
+		$getToken = ( $casToken === self::PASS_BY_REF );
 		$casToken = null;
-
-		return $this->client->get( $this->validateKeyEncoding( $key ), $casToken );
+		// T257003: only require "gets" (instead of "get") when a CAS token is needed
+		return $getToken
+			? $this->client->get( $this->validateKeyEncoding( $key ), $casToken )
+			: $this->client->get( $this->validateKeyEncoding( $key ) );
 	}
 
 	protected function doSet( $key, $value, $exptime = 0, $flags = 0 ) {
diff --git a/includes/libs/objectcache/RESTBagOStuff.php b/includes/libs/objectcache/RESTBagOStuff.php
index 4e0add99231..266fa06aaba 100644
--- a/includes/libs/objectcache/RESTBagOStuff.php
+++ b/includes/libs/objectcache/RESTBagOStuff.php
@@ -137,6 +137,7 @@ class RESTBagOStuff extends MediumSpecificBagOStuff {
 	}
 
 	protected function doGet( $key, $flags = 0, &$casToken = null ) {
+		$getToken = ( $casToken === self::PASS_BY_REF );
 		$casToken = null;
 
 		$req = [
@@ -150,7 +151,9 @@ class RESTBagOStuff extends MediumSpecificBagOStuff {
 			if ( is_string( $rbody ) ) {
 				$value = $this->decodeBody( $rbody );
 				/// @FIXME: use some kind of hash or UUID header as CAS token
-				$casToken = ( $value !== false ) ? $rbody : null;
+				if ( $getToken && $value !== false ) {
+					$casToken = $rbody;
+				}
 
 				return $value;
 			}
diff --git a/includes/libs/objectcache/RedisBagOStuff.php b/includes/libs/objectcache/RedisBagOStuff.php
index c380592d33e..328f5cfa782 100644
--- a/includes/libs/objectcache/RedisBagOStuff.php
+++ b/includes/libs/objectcache/RedisBagOStuff.php
@@ -89,6 +89,7 @@ class RedisBagOStuff extends MediumSpecificBagOStuff {
 	}
 
 	protected function doGet( $key, $flags = 0, &$casToken = null ) {
+		$getToken = ( $casToken === self::PASS_BY_REF );
 		$casToken = null;
 
 		$conn = $this->getConnection( $key );
@@ -99,7 +100,9 @@ class RedisBagOStuff extends MediumSpecificBagOStuff {
 		$e = null;
 		try {
 			$value = $conn->get( $key );
-			$casToken = $value;
+			if ( $getToken && $value !== false ) {
+				$casToken = $value;
+			}
 			$result = $this->unserialize( $value );
 		} catch ( RedisException $e ) {
 			$result = false;
diff --git a/includes/libs/objectcache/WinCacheBagOStuff.php b/includes/libs/objectcache/WinCacheBagOStuff.php
index ddc1cc47940..db22a4f64b7 100644
--- a/includes/libs/objectcache/WinCacheBagOStuff.php
+++ b/includes/libs/objectcache/WinCacheBagOStuff.php
@@ -34,6 +34,7 @@ class WinCacheBagOStuff extends MediumSpecificBagOStuff {
 	}
 
 	protected function doGet( $key, $flags = 0, &$casToken = null ) {
+		$getToken = ( $casToken === self::PASS_BY_REF );
 		$casToken = null;
 
 		$blob = wincache_ucache_get( $key );
@@ -42,7 +43,7 @@ class WinCacheBagOStuff extends MediumSpecificBagOStuff {
 		}
 
 		$value = $this->unserialize( $blob );
-		if ( $value !== false ) {
+		if ( $getToken && $value !== false ) {
 			$casToken = (string)$blob; // don't bother hashing this
 		}
 
@@ -54,7 +55,7 @@ class WinCacheBagOStuff extends MediumSpecificBagOStuff {
 			return false;
 		}
 
-		$curCasToken = null; // passed by reference
+		$curCasToken = self::PASS_BY_REF; // passed by reference
 		$this->doGet( $key, self::READ_LATEST, $curCasToken );
 		if ( $casToken === $curCasToken ) {
 			$success = $this->set( $key, $value, $exptime, $flags );
diff --git a/includes/libs/objectcache/utils/MemcachedClient.php b/includes/libs/objectcache/utils/MemcachedClient.php
index 2c4085433ea..491db19e608 100644
--- a/includes/libs/objectcache/utils/MemcachedClient.php
+++ b/includes/libs/objectcache/utils/MemcachedClient.php
@@ -465,6 +465,8 @@ class MemcachedClient {
 	 * @return mixed
 	 */
 	public function get( $key, &$casToken = null ) {
+		$getToken = ( func_num_args() >= 2 );
+
 		if ( $this->_debug ) {
 			$this->_debugprint( "get($key)" );
 		}
@@ -491,7 +493,8 @@ class MemcachedClient {
 			$this->stats['get'] = 1;
 		}
 
-		$cmd = "gets $key\r\n";
+		$cmd = $getToken ? "gets" : "get";
+		$cmd .= " $key\r\n";
 		if ( !$this->_fwrite( $sock, $cmd ) ) {
 			return false;
 		}
@@ -551,7 +554,7 @@ class MemcachedClient {
 		$gather = array();
 		// Send out the requests
 		foreach ( $socks as $sock ) {
-			$cmd = 'gets';
+			$cmd = 'get';
 			foreach ( $sock_keys[intval( $sock )] as $key ) {
 				$cmd .= ' ' . $key;
 			}
@@ -565,7 +568,7 @@ class MemcachedClient {
 		// Parse responses
 		$val = array();
 		foreach ( $gather as $sock ) {
-			$this->_load_items( $sock, $val, $casToken );
+			$this->_load_items( $sock, $val );
 		}
 
 		if ( $this->_debug ) {
@@ -968,7 +971,7 @@ class MemcachedClient {
 				 * to stop reading (right after "END") and we return right after that.
 				 */
 				return false;
-			} elseif ( preg_match( '/^VALUE (\S+) (\d+) (\d+) (\d+)$/', $decl, $match ) ) {
+			} elseif ( preg_match( '/^VALUE (\S+) (\d+) (\d+)(?: (\d+))?$/', $decl, $match ) ) {
 				/*
 				 * Read all data returned. This can be either one or multiple values.
 				 * Save all that data (in an array) to be processed later: we'll first
@@ -980,7 +983,7 @@ class MemcachedClient {
 					$match[1], // rkey
 					$match[2], // flags
 					$match[3], // len
-					$match[4], // casToken
+					$match[4] ?? null, // casToken (appears with "gets" but not "get")
 					$this->_fread( $sock, $match[3] + 2 ), // data
 				);
 			} elseif ( $decl == "END" ) {
@@ -993,7 +996,7 @@ class MemcachedClient {
 				 * meaningful return values.
 				 */
 				foreach ( $results as $vars ) {
-					list( $rkey, $flags, $len, $casToken, $data ) = $vars;
+					list( $rkey, $flags, /* length */, $casToken, $data ) = $vars;
 
 					if ( $data === false || substr( $data, -2 ) !== "\r\n" ) {
 						$this->_handle_error( $sock,
diff --git a/includes/libs/objectcache/wancache/WANObjectCache.php b/includes/libs/objectcache/wancache/WANObjectCache.php
index ae764ca901d..ad783d2bbc2 100644
--- a/includes/libs/objectcache/wancache/WANObjectCache.php
+++ b/includes/libs/objectcache/wancache/WANObjectCache.php
@@ -201,7 +201,7 @@ class WANObjectCache implements
 	/** @var string Default process cache name and max key count */
 	private const PC_PRIMARY = 'primary:1000';
 
-	/** @var int Idion for get()/getMulti() to return extra information by reference */
+	/** @var int Idiom for get()/getMulti() to return extra information by reference */
 	public const PASS_BY_REF = -1;
 
 	/** @var int Use twemproxy-style Hash Tag key scheme (e.g. "{...}") */
diff --git a/includes/objectcache/SqlBagOStuff.php b/includes/objectcache/SqlBagOStuff.php
index 88604f084db..e505064678b 100644
--- a/includes/objectcache/SqlBagOStuff.php
+++ b/includes/objectcache/SqlBagOStuff.php
@@ -259,14 +259,16 @@ class SqlBagOStuff extends MediumSpecificBagOStuff {
 	}
 
 	protected function doGet( $key, $flags = 0, &$casToken = null ) {
+		$getToken = ( $casToken === self::PASS_BY_REF );
 		$casToken = null;
 
 		$blobs = $this->fetchBlobMulti( [ $key ] );
 		if ( array_key_exists( $key, $blobs ) ) {
 			$blob = $blobs[$key];
 			$value = $this->unserialize( $blob );
-
-			$casToken = ( $value !== false ) ? $blob : null;
+			if ( $getToken && $value !== false ) {
+				$casToken = $blob;
+			}
 
 			return $value;
 		}