diff --git a/patches.txt b/patches.txt
index 85c95658a..e2c9c1373 100644
--- a/patches.txt
+++ b/patches.txt
@@ -9,3 +9,4 @@ Patches:
 - SabreXML: Fix invalid PHP docs https://github.com/fruux/sabre-xml/pull/128
 - SabreXML: Prevent infinite loops for empty props element https://github.com/fruux/sabre-xml/pull/132
 - ZipStreamer: Fix zip generation for 7zip https://github.com/McNetic/PHPZipStreamer/pull/39
+- scssphp: Fix Trying to access array offset on value of type null https://github.com/scssphp/scssphp/commit/05a5d11ea7f68c52fdb6a5ca35cf46613b608445
diff --git a/scssphp/scssphp/src/Compiler.php b/scssphp/scssphp/src/Compiler.php
index 8655ef9df..6e4b729ec 100644
--- a/scssphp/scssphp/src/Compiler.php
+++ b/scssphp/scssphp/src/Compiler.php
@@ -2712,7 +2712,6 @@ protected function shouldEval($value)
      */
     protected function reduce($value, $inExp = false)
     {
-
         switch ($value[0]) {
             case Type::T_EXPRESSION:
                 list(, $op, $left, $right, $inParens) = $value;
@@ -6170,10 +6169,10 @@ protected function libStrLength($args)
         return new Node\Number(strlen($stringContent), '');
     }
 
-    protected static $libStrSlice = ['string', 'start-at', 'end-at:null'];
+    protected static $libStrSlice = ['string', 'start-at', 'end-at:-1'];
     protected function libStrSlice($args)
     {
-        if (isset($args[2]) && $args[2][1] == 0) {
+        if (isset($args[2]) && ! $args[2][1]) {
             return static::$nullString;
         }
 
@@ -6186,7 +6185,7 @@ protected function libStrSlice($args)
             $start--;
         }
 
-        $end    = (int) $args[2][1];
+        $end    = isset($args[2]) ? (int) $args[2][1] : -1;
         $length = $end < 0 ? $end + 1 : ($end > 0 ? $end - $start : $end);
 
         $string[2] = $length