diff --git a/src/FFMpeg/Media/AbstractVideo.php b/src/FFMpeg/Media/AbstractVideo.php
index 2b11bd4..e02bbe9 100644
--- a/src/FFMpeg/Media/AbstractVideo.php
+++ b/src/FFMpeg/Media/AbstractVideo.php
@@ -206,7 +206,7 @@ abstract class AbstractVideo extends Audio
         $videoFilterVars = $videoFilterProcesses = array();
         for ($i = 0; $i < count($commands); $i++) {
             $command = $commands[$i];
-            if ($command == '-vf') {
+            if ($command === '-vf') {
                 $commandSplits = explode(";", $commands[$i + 1]);
                 if (count($commandSplits) == 1) {
                     $commandSplit = $commandSplits[0];