diff --git a/lib/Vizhash16x16.php b/lib/Vizhash16x16.php
index b61fd56b..2d296af8 100644
--- a/lib/Vizhash16x16.php
+++ b/lib/Vizhash16x16.php
@@ -109,9 +109,9 @@ class Vizhash16x16
         for ($i = 0; $i < 7; ++$i) {
             $action = $this->getInt();
             $color  = imagecolorallocate($image, $r, $g, $b);
-            $r      = $r0      = ($r0 + $this->getInt() / 25) % 256;
-            $g      = $g0      = ($g0 + $this->getInt() / 25) % 256;
-            $b      = $b0      = ($b0 + $this->getInt() / 25) % 256;
+            $r      = $r0      = ((int) $r0 + $this->getInt() / 25) % 256;
+            $g      = $g0      = ((int) $g0 + $this->getInt() / 25) % 256;
+            $b      = $b0      = ((int) $b0 + $this->getInt() / 25) % 256;
             $this->drawshape($image, $action, $color);
         }
 
@@ -136,7 +136,7 @@ class Vizhash16x16
     {
         $v = $this->VALUES[$this->VALUES_INDEX];
         ++$this->VALUES_INDEX;
-        $this->VALUES_INDEX %= count($this->VALUES); // Warp around the array
+        $this->VALUES_INDEX %= count($this->VALUES); // Wrap around the array
         return $v;
     }
 
@@ -148,7 +148,7 @@ class Vizhash16x16
      */
     private function getX()
     {
-        return $this->width * $this->getInt() / 256;
+        return (int) $this->width * $this->getInt() / 256;
     }
 
     /**
@@ -159,7 +159,7 @@ class Vizhash16x16
      */
     private function getY()
     {
-        return $this->height * $this->getInt() / 256;
+        return (int) $this->height * $this->getInt() / 256;
     }
 
     /**
@@ -190,9 +190,9 @@ class Vizhash16x16
             ($color2[2] - $color1[2]) / $size,
         );
         for ($i = 0; $i < $size; ++$i) {
-            $r = $color1[0] + ($diffs[0] * $i);
-            $g = $color1[1] + ($diffs[1] * $i);
-            $b = $color1[2] + ($diffs[2] * $i);
+            $r = $color1[0] + ((int) $diffs[0] * $i);
+            $g = $color1[1] + ((int) $diffs[1] * $i);
+            $b = $color1[2] + ((int) $diffs[2] * $i);
             if ($direction == 'h') {
                 imageline($img, $i, 0, $i, $sizeinv, imagecolorallocate($img, $r, $g, $b));
             } else {
@@ -222,7 +222,7 @@ class Vizhash16x16
                 break;
             case 3:
                 $points = array($this->getX(), $this->getY(), $this->getX(), $this->getY(), $this->getX(), $this->getY(), $this->getX(), $this->getY());
-                imagefilledpolygon($image, $points, 4, $color);
+                version_compare(PHP_VERSION, '8.1', '<') ? imagefilledpolygon($image, $points, 4, $color) : imagefilledpolygon($image, $points, $color);
                 break;
             default:
                 $start = $this->getInt() * 360 / 256;