diff --git a/system/Entity.php b/system/Entity.php
index fa54c2dd270b..5486308b31b5 100644
--- a/system/Entity.php
+++ b/system/Entity.php
@@ -239,6 +239,23 @@ protected function hasPropertyChanged(string $key, $value = null)
 	{
 		return ! (($this->_original[$key] === null && $value === null) || $this->_original[$key] === $value);
 	}
+	
+	//--------------------------------------------------------------------
+
+	/**
+	 * Gets original property value or $defaultValue specified by parameter if original value is not set OR null
+	 *
+	 * @param string $key
+	 * @param null $defaultValue
+	 *
+	 * @return mixed
+	 */
+	public function getOriginalValue(string $key, $defaultValue = null)
+	{
+		return $this->_original[$key] ?? $defaultValue;
+	}
+	
+	//--------------------------------------------------------------------
 
 	/**
 	 * Magic method to allow retrieval of protected and private
@@ -373,6 +390,7 @@ public function __set(string $key, $value = null)
 	 * attribute will be reset to that default value.
 	 *
 	 * @param string $key
+	 * @throws \ReflectionException
 	 */
 	public function __unset(string $key)
 	{
diff --git a/system/Model.php b/system/Model.php
index eb69d717ae1a..9d3ea38bd365 100644
--- a/system/Model.php
+++ b/system/Model.php
@@ -443,7 +443,7 @@ public function set($key, $value = '', bool $escape = null)
 	}
 
 	//--------------------------------------------------------------------
-
+	
 	/**
 	 * A convenience method that will attempt to determine whether the
 	 * data should be inserted or updated. Will work with either
@@ -458,26 +458,49 @@ public function set($key, $value = '', bool $escape = null)
 	 */
 	public function save($data)
 	{
+		$originalPrimaryKey = null;
 		// If $data is using a custom class with public or protected
 		// properties representing the table elements, we need to grab
 		// them as an array.
-		if (is_object($data) && ! $data instanceof \stdClass)
+		if (is_object($data))
 		{
-			$data = static::classToArray($data, $this->primaryKey, $this->dateFormat);
+			if( ! $data instanceof \stdClass)
+			{
+
+				$originalPrimaryKey = method_exists($data, 'getOriginalValue') ?
+					$data->getOriginalValue($this->primaryKey) :
+					($data->{$this->primaryKey} ?? null);
+
+				$data = static::classToArray($data, $this->primaryKey, $this->dateFormat);
+			}
+			else
+			{
+				$originalPrimaryKey = $data->{$this->primaryKey} ?? null;
+			}
+
+		}
+		else if(is_array($data))
+		{
+			$originalPrimaryKey = $data[$this->primaryKey] ?? null;
 		}
 
-		if (empty($data))
+		// If originalPrimaryKey is not null there is only one item in $data array and
+		// $data[$primaryKey] = $originalPrimaryKey
+		// then nothing has been changed in other case someone wants to update only primaryKey value.
+		// We do not have possibilities to check object here :(
+		if(empty($data) || ($originalPrimaryKey !== null && is_array($data) && ! empty($data[$this->primaryKey]) && count($data) === 1 && $data[$this->primaryKey] === $originalPrimaryKey))
 		{
 			return true;
 		}
 
-		if (is_object($data) && isset($data->{$this->primaryKey}))
+		if (is_object($data) && !empty($originalPrimaryKey))
 		{
-			$response = $this->update($data->{$this->primaryKey}, $data);
+			$response = $this->update($originalPrimaryKey, $data);
 		}
-		elseif (is_array($data) && ! empty($data[$this->primaryKey]))
+		// Adding support for UPDATE table SET primaryKey = 'newVal' WHERE primaryKey = 'oldVal'
+		elseif (is_array($data) && ! empty($originalPrimaryKey))
 		{
-			$response = $this->update($data[$this->primaryKey], $data);
+			$response = $this->update($originalPrimaryKey, $data);
 		}
 		else
 		{
@@ -487,6 +510,7 @@ public function save($data)
 		return $response;
 	}
 
+
 	/**
 	 * Takes a class an returns an array of it's public and protected
 	 * properties as an array suitable for use in creates and updates.