diff --git a/application/Config/Mimes.php b/application/Config/Mimes.php
index 25a9224f035c..bcb232181d92 100644
--- a/application/Config/Mimes.php
+++ b/application/Config/Mimes.php
@@ -302,13 +302,22 @@ public static function guessTypeFromExtension(string $extension)
 	 * Attempts to determine the best file extension for a given mime type.
 	 *
 	 * @param string $type
+	 * @param string $proposed_extension - default extension (in case there is more than one with the same mime type)
 	 *
 	 * @return string|null The extension determined, or null if unable to match.
 	 */
-	public static function guessExtensionFromType(string $type)
+	public static function guessExtensionFromType(string $type, ?string $proposed_extension = null)
 	{
+
 		$type = trim(strtolower($type), '. ');
 
+		$proposed_extension = trim(strtolower($proposed_extension));
+
+		if(!is_null($proposed_extension) && array_key_exists($proposed_extension, self::$mimes) && in_array($type, self::$mimes[$proposed_extension]))
+		{
+			return $proposed_extension;
+		}
+
 		foreach (self::$mimes as $ext => $types)
 		{
 			if (is_string($types) && $types == $type)
@@ -324,6 +333,7 @@ public static function guessExtensionFromType(string $type)
 		return null;
 	}
 
+
 	//--------------------------------------------------------------------
 
 
diff --git a/system/HTTP/Files/UploadedFile.php b/system/HTTP/Files/UploadedFile.php
index 1e309616fd10..8d8d9087c611 100644
--- a/system/HTTP/Files/UploadedFile.php
+++ b/system/HTTP/Files/UploadedFile.php
@@ -342,12 +342,21 @@ public function getTempName(): string
 	 *
 	 * Is simply an alias for guessExtension for a safer method
 	 * than simply relying on the provided extension.
+	 * Additionaly it will return clientExtension in case if there are
+	 * other extensions withe the same mime type. 
 	 */
-	public function getExtension()
+	public function getExtension() : string
 	{
 		return $this->guessExtension();
 	}
 
+	public function guessExtension(): string
+	{
+		return \Config\Mimes::guessExtensionFromType($this->getMimeType(), $this->getClientExtension());
+	}
+
+	//--------------------------------------------------------------------
+
 	/**
 	 * Returns the original file extension, based on the file name that
 	 * was uploaded. This is NOT a trusted source.