diff --git a/README.md b/README.md
index 82fdb8a..40df3d9 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@
 **Tags:** cache, plugin, redis
 **Requires at least:** 3.0.1
 **Tested up to:** 6.2
-**Stable tag:** 1.3.6-dev
+**Stable tag:** 1.4.0-dev
 **License:** GPLv2 or later
 **License URI:** http://www.gnu.org/licenses/gpl-2.0.html
 
@@ -105,6 +105,7 @@ There's a known issue with WordPress `alloptions` cache design. Specifically, a
 ## Changelog ##
 
 ### Latest ###
+* Add support for `flush_runtime` and `flush_group` functions [[#405](https://github.com/pantheon-systems/wp-redis/pull/405)]
 * Update Composer dependencies [[#401](https://github.com/pantheon-systems/wp-redis/pull/394)]
 
 ### 1.3.5 (April 6, 2023) ###
@@ -229,3 +230,6 @@ Declare `wp_cache_supports` function and support features. [[#378](https://githu
 
 ### 0.1 ###
 * Initial commit of working code for the benefit of all.
+
+## Latest ##
+WP Redis 1.4.0-dev adds support for the `flush_runtime` and `flush_group` functions. If you've copied `object-cache.php` and made your own changes, be sure to copy these additions over as well.
diff --git a/object-cache.php b/object-cache.php
index e849c2c..5211a69 100644
--- a/object-cache.php
+++ b/object-cache.php
@@ -157,6 +157,35 @@ function wp_cache_get_multiple( $keys, $group = '', $force = false ) {
 	return $wp_object_cache->get_multiple( $keys, $group, $force );
 }
 
+/**
+ * Removes all cache items from the in-memory runtime cache.
+ *
+ * @see WP_Object_Cache::flush()
+ *
+ * @return bool True on success, false on failure.
+ */
+function wp_cache_flush_runtime() {
+	return wp_cache_flush();
+}
+
+/**
+ * Removes all cache items in a group, if the object cache implementation supports it.
+ *
+ * Before calling this function, always check for group flushing support using the
+ * `wp_cache_supports( 'flush_group' )` function.
+ *
+ * @see WP_Object_Cache::flush_group()
+ * @global WP_Object_Cache $wp_object_cache Object cache global instance.
+ *
+ * @param string $group Name of group to remove from cache.
+ * @return bool True if group was flushed, false otherwise.
+ */
+function wp_cache_flush_group( $group ) {
+	global $wp_object_cache;
+
+	return $wp_object_cache->flush_group( $group );
+}
+
 /**
  * Increment numeric cache item's value
  *
@@ -304,13 +333,13 @@ function wp_cache_reset() {
 function wp_cache_supports( $feature ) {
 	switch ( $feature ) {
 		case 'get_multiple':
+		case 'flush_runtime':
+		case 'flush_group':
 			return true;
 
 		case 'add_multiple':
 		case 'set_multiple':
 		case 'delete_multiple':
-		case 'flush_runtime':
-		case 'flush_group':
 		default:
 			return false;
 	}
@@ -630,6 +659,31 @@ public function flush( $redis = true ) {
 		return true;
 	}
 
+	/**
+	 * Removes all cache items in a group.
+	 *
+	 * @param string $group Name of group to remove from cache.
+	 * @return true Always returns true.
+	 */
+	public function flush_group( $group ) {
+		if ( ! $this->_should_use_redis_hashes( $group ) ) {
+			return false;
+		}
+
+		$multisite_safe_group = $this->multisite && ! isset( $this->global_groups[ $group ] ) ? $this->blog_prefix . $group : $group;
+		$redis_safe_group     = $this->_key( '', $group );
+		if ( $this->_should_persist( $group ) ) {
+			$result = $this->_call_redis( 'del', $redis_safe_group );
+			if ( 1 !== $result ) {
+				return false;
+			}
+		} elseif ( ! $this->_should_persist( $group ) && ! isset( $this->cache[ $multisite_safe_group ] ) ) {
+			return false;
+		}
+		unset( $this->cache[ $multisite_safe_group ] );
+		return true;
+	}
+
 	/**
 	 * Retrieves the cache contents, if it exists
 	 *
diff --git a/readme.txt b/readme.txt
index 9d5ccfc..552219b 100644
--- a/readme.txt
+++ b/readme.txt
@@ -3,7 +3,7 @@ Contributors: getpantheon, danielbachhuber, mboynes, Outlandish Josh, jspellman,
 Tags: cache, plugin, redis
 Requires at least: 3.0.1
 Tested up to: 6.2
-Stable tag: 1.3.6-dev
+Stable tag: 1.4.0-dev
 License: GPLv2 or later
 License URI: http://www.gnu.org/licenses/gpl-2.0.html
 
@@ -103,6 +103,7 @@ There's a known issue with WordPress `alloptions` cache design. Specifically, a
 == Changelog ==
 
 = Latest =
+* Add support for `flush_runtime` and `flush_group` functions [[#405](https://github.com/pantheon-systems/wp-redis/pull/405)]
 * Update Composer dependencies [[#401](https://github.com/pantheon-systems/wp-redis/pull/394)]
 
 = 1.3.5 (April 6, 2023) =
@@ -224,3 +225,8 @@ There's a known issue with WordPress `alloptions` cache design. Specifically, a
 
 = 0.1 =
 * Initial commit of working code for the benefit of all.
+
+== Upgrade Notice ==
+
+= Latest =
+WP Redis 1.4.0-dev adds support for the `flush_runtime` and `flush_group` functions. If you've copied `object-cache.php` and made your own changes, be sure to copy these additions over as well.
\ No newline at end of file
diff --git a/tests/phpunit/test-cache.php b/tests/phpunit/test-cache.php
index 1e5edca..fac2e28 100644
--- a/tests/phpunit/test-cache.php
+++ b/tests/phpunit/test-cache.php
@@ -391,6 +391,67 @@ public function test_flush() {
 		}
 	}
 
+	public function test_wp_cache_flush_runtime() {
+		// Add some data to the cache
+		$data = array(
+			rand_str() => rand_str(),
+			rand_str() => rand_str()
+		);
+
+		foreach ( $data as $key => $value ) {
+			wp_cache_set( $key, $value, 'test_wp_cache_flush_runtime' );
+		}
+
+		// Verify that the cache contains the data
+		foreach ( $data as $key => $value ) {
+			$this->assertEquals( $value, wp_cache_get( $key, 'test_wp_cache_flush_runtime' ) );
+		}
+
+		// Flush the cache
+		wp_cache_flush_runtime();
+
+		// Verify that the cache is now empty
+		foreach ($data as $key => $value) {
+			$this->assertFalse( wp_cache_get( $key, 'test_wp_cache_flush_runtime' ) );
+		}
+	}
+
+	public function test_wp_cache_flush_group() {
+		$key1   = rand_str();
+		$val1   = rand_str();
+		$key2   = rand_str();
+		$val2   = rand_str();
+		$key3   = rand_str();
+		$val3   = rand_str();
+		$group  = 'foo';
+		$group2 = 'bar';
+
+		if ( ! defined( 'WP_REDIS_USE_CACHE_GROUPS' ) || ! WP_REDIS_USE_CACHE_GROUPS ) {
+			$GLOBALS['wp_object_cache']->add_redis_hash_groups( array( $group, $group2 ) );
+		}
+
+		// Set up the values
+		wp_cache_set( $key1, $val1, $group );
+		wp_cache_set( $key2, $val2, $group );
+		wp_cache_set( $key3, $val3, $group2 );
+		$this->assertEquals( $val1, wp_cache_get( $key1, $group ) );
+		$this->assertEquals( $val2, wp_cache_get( $key2, $group ) );
+		$this->assertEquals( $val3, wp_cache_get( $key3, $group2 ) );
+
+		$this->assertTrue( wp_cache_flush_group( $group ) );
+
+		$this->assertFalse( wp_cache_get( $key1, $group ) );
+		$this->assertFalse( wp_cache_get( $key2, $group ) );
+		$this->assertEquals( $val3, wp_cache_get( $key3, $group2 ) );
+
+		// _call_redis( 'delete' ) always returns true when Redis isn't available
+		if ( class_exists( 'Redis' ) ) {
+			$this->assertFalse( wp_cache_flush_group( $group ) );
+		} else {
+			$this->assertTrue( wp_cache_flush_group( $group ) );
+		}
+	}
+
 	// Make sure objects are cloned going to and from the cache
 	public function test_object_refs() {
 		$key           = rand_str();
diff --git a/wp-redis.php b/wp-redis.php
index 95fc714..ae9dd48 100644
--- a/wp-redis.php
+++ b/wp-redis.php
@@ -3,7 +3,7 @@
  * Plugin Name: WP Redis
  * Plugin URI: http://github.com/pantheon-systems/wp-redis/
  * Description: WordPress Object Cache using Redis. Requires the PhpRedis extension (https://github.com/phpredis/phpredis).
- * Version: 1.3.6-dev
+ * Version: 1.4.0-dev
  * Author: Pantheon, Josh Koenig, Matthew Boynes, Daniel Bachhuber, Alley Interactive
  * Author URI: https://pantheon.io/
  */