diff --git a/system/Cache/Handlers/DummyHandler.php b/system/Cache/Handlers/DummyHandler.php
index 5f6e50d5762a..1ac00a56419b 100644
--- a/system/Cache/Handlers/DummyHandler.php
+++ b/system/Cache/Handlers/DummyHandler.php
@@ -65,7 +65,7 @@ public function remember(string $key, int $ttl, Closure $callback)
 	 * @param mixed   $value The data to save
 	 * @param integer $ttl   Time To Live, in seconds (default 60)
 	 *
-	 * @return mixed
+	 * @return boolean Success or failure
 	 */
 	public function save(string $key, $value, int $ttl = 60)
 	{
@@ -79,7 +79,7 @@ public function save(string $key, $value, int $ttl = 60)
 	 *
 	 * @param string $key Cache item name
 	 *
-	 * @return boolean
+	 * @return boolean Success or failure
 	 */
 	public function delete(string $key)
 	{
@@ -135,7 +135,7 @@ public function decrement(string $key, int $offset = 1)
 	/**
 	 * Will delete all items in the entire cache.
 	 *
-	 * @return boolean
+	 * @return boolean Success or failure
 	 */
 	public function clean()
 	{
diff --git a/system/Cache/Handlers/FileHandler.php b/system/Cache/Handlers/FileHandler.php
index d184d19f0dd4..f4f6751dffa3 100644
--- a/system/Cache/Handlers/FileHandler.php
+++ b/system/Cache/Handlers/FileHandler.php
@@ -111,7 +111,7 @@ public function get(string $key)
 	 * @param mixed   $value The data to save
 	 * @param integer $ttl   Time To Live, in seconds (default 60)
 	 *
-	 * @return mixed
+	 * @return boolean Success or failure
 	 */
 	public function save(string $key, $value, int $ttl = 60)
 	{
@@ -149,7 +149,7 @@ public function save(string $key, $value, int $ttl = 60)
 	 *
 	 * @param string $key Cache item name
 	 *
-	 * @return boolean
+	 * @return boolean Success or failure
 	 */
 	public function delete(string $key)
 	{
@@ -253,7 +253,7 @@ public function decrement(string $key, int $offset = 1)
 	/**
 	 * Will delete all items in the entire cache.
 	 *
-	 * @return boolean
+	 * @return boolean Success or failure
 	 */
 	public function clean()
 	{
diff --git a/system/Cache/Handlers/MemcachedHandler.php b/system/Cache/Handlers/MemcachedHandler.php
index 8758b01423cc..42e8cddbb89e 100644
--- a/system/Cache/Handlers/MemcachedHandler.php
+++ b/system/Cache/Handlers/MemcachedHandler.php
@@ -202,7 +202,7 @@ public function get(string $key)
 	 * @param mixed   $value The data to save
 	 * @param integer $ttl   Time To Live, in seconds (default 60)
 	 *
-	 * @return mixed
+	 * @return boolean Success or failure
 	 */
 	public function save(string $key, $value, int $ttl = 60)
 	{
@@ -238,7 +238,7 @@ public function save(string $key, $value, int $ttl = 60)
 	 *
 	 * @param string $key Cache item name
 	 *
-	 * @return boolean
+	 * @return boolean Success or failure
 	 */
 	public function delete(string $key)
 	{
@@ -313,7 +313,7 @@ public function decrement(string $key, int $offset = 1)
 	/**
 	 * Will delete all items in the entire cache.
 	 *
-	 * @return boolean
+	 * @return boolean Success or failure
 	 */
 	public function clean()
 	{
diff --git a/system/Cache/Handlers/PredisHandler.php b/system/Cache/Handlers/PredisHandler.php
index 5b932733cc88..667650082b01 100644
--- a/system/Cache/Handlers/PredisHandler.php
+++ b/system/Cache/Handlers/PredisHandler.php
@@ -138,7 +138,7 @@ public function get(string $key)
 	 * @param mixed   $value The data to save
 	 * @param integer $ttl   Time To Live, in seconds (default 60)
 	 *
-	 * @return mixed
+	 * @return boolean Success or failure
 	 */
 	public function save(string $key, $value, int $ttl = 60)
 	{
@@ -176,7 +176,7 @@ public function save(string $key, $value, int $ttl = 60)
 	 *
 	 * @param string $key Cache item name
 	 *
-	 * @return boolean
+	 * @return boolean Success or failure
 	 */
 	public function delete(string $key)
 	{
@@ -242,7 +242,7 @@ public function decrement(string $key, int $offset = 1)
 	/**
 	 * Will delete all items in the entire cache.
 	 *
-	 * @return boolean
+	 * @return boolean Success or failure
 	 */
 	public function clean()
 	{
diff --git a/system/Cache/Handlers/RedisHandler.php b/system/Cache/Handlers/RedisHandler.php
index d5fad5b86ce8..aeb10d6cf7cf 100644
--- a/system/Cache/Handlers/RedisHandler.php
+++ b/system/Cache/Handlers/RedisHandler.php
@@ -169,7 +169,7 @@ public function get(string $key)
 	 * @param mixed   $value The data to save
 	 * @param integer $ttl   Time To Live, in seconds (default 60)
 	 *
-	 * @return mixed
+	 * @return boolean Success or failure
 	 */
 	public function save(string $key, $value, int $ttl = 60)
 	{
@@ -212,7 +212,7 @@ public function save(string $key, $value, int $ttl = 60)
 	 *
 	 * @param string $key Cache item name
 	 *
-	 * @return boolean
+	 * @return boolean Success or failure
 	 */
 	public function delete(string $key)
 	{
@@ -288,7 +288,7 @@ public function decrement(string $key, int $offset = 1)
 	/**
 	 * Will delete all items in the entire cache.
 	 *
-	 * @return boolean
+	 * @return boolean Success or failure
 	 */
 	public function clean()
 	{
diff --git a/system/Cache/Handlers/WincacheHandler.php b/system/Cache/Handlers/WincacheHandler.php
index f6ca9d8d5d40..77fae29ccb84 100644
--- a/system/Cache/Handlers/WincacheHandler.php
+++ b/system/Cache/Handlers/WincacheHandler.php
@@ -83,7 +83,7 @@ public function get(string $key)
 	 * @param mixed   $value The data to save
 	 * @param integer $ttl   Time To Live, in seconds (default 60)
 	 *
-	 * @return mixed
+	 * @return boolean Success or failure
 	 *
 	 * @codeCoverageIgnore
 	 */
@@ -101,7 +101,7 @@ public function save(string $key, $value, int $ttl = 60)
 	 *
 	 * @param string $key Cache item name
 	 *
-	 * @return boolean
+	 * @return boolean Success or failure
 	 *
 	 * @codeCoverageIgnore
 	 */
@@ -179,7 +179,7 @@ public function decrement(string $key, int $offset = 1)
 	 *
 	 * @return boolean
 	 *
-	 * @codeCoverageIgnore
+	 * @boolean Success or failure
 	 */
 	public function clean()
 	{