diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index 0405354..0a16ff9 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -1,4 +1,4 @@
 parameters:
   paths:
     - src
-  level: 4
+  level: 5
diff --git a/src/Renderers/PngRenderer.php b/src/Renderers/PngRenderer.php
index 2009635..59c8269 100644
--- a/src/Renderers/PngRenderer.php
+++ b/src/Renderers/PngRenderer.php
@@ -47,7 +47,7 @@ public function useGd()
 
     public function render(Barcode $barcode, int $widthFactor = 2, int $height = 30): string
     {
-        $width = round($barcode->getWidth() * $widthFactor);
+        $width = (int)round($barcode->getWidth() * $widthFactor);
 
         if ($this->useImagick) {
             $imagickBarsShape = new ImagickDraw();
@@ -61,11 +61,11 @@ public function render(Barcode $barcode, int $widthFactor = 2, int $height = 30)
         $positionHorizontal = 0;
         /** @var BarcodeBar $bar */
         foreach ($barcode->getBars() as $bar) {
-            $barWidth = round(($bar->getWidth() * $widthFactor), 3);
+            $barWidth = (int)round(($bar->getWidth() * $widthFactor));
 
             if ($bar->isBar() && $barWidth > 0) {
-                $y = round(($bar->getPositionVertical() * $height / $barcode->getHeight()), 3);
-                $barHeight = round(($bar->getHeight() * $height / $barcode->getHeight()), 3);
+                $y = (int)round(($bar->getPositionVertical() * $height / $barcode->getHeight()));
+                $barHeight = (int)round(($bar->getHeight() * $height / $barcode->getHeight()));
 
                 // draw a vertical bar
                 if ($this->useImagick) {
diff --git a/src/Types/TypeITF14.php b/src/Types/TypeITF14.php
index 50f7b2e..7740efa 100644
--- a/src/Types/TypeITF14.php
+++ b/src/Types/TypeITF14.php
@@ -60,7 +60,7 @@ public function getBarcode(string $code): Barcode
             }
 
             foreach (str_split($pmixed) as $width) {
-                $barcode->addBar(new BarcodeBar($width, 1, $drawBar));
+                $barcode->addBar(new BarcodeBar(intval($width), 1, $drawBar));
                 $drawBar = ! $drawBar;
             }
         }
@@ -73,7 +73,7 @@ private function getChecksum(string $code): string
         $total = 0;
 
         for ($charIndex = 0; $charIndex <= (strlen($code) - 1); $charIndex++) {
-            $integerOfChar = intval($code . substr($charIndex, 1));
+            $integerOfChar = intval($code . substr(strval($charIndex), 1));
             $total += $integerOfChar * (($charIndex === 0 || $charIndex % 2 === 0) ? 3 : 1);
         }
 
diff --git a/src/Types/TypeIntelligentMailBarcode.php b/src/Types/TypeIntelligentMailBarcode.php
index 7d74829..9160e14 100644
--- a/src/Types/TypeIntelligentMailBarcode.php
+++ b/src/Types/TypeIntelligentMailBarcode.php
@@ -333,9 +333,9 @@ public function getBarcode(string $code): Barcode
                 throw new BarcodeException('Routing code unknown');
         }
 
-        $binary_code = bcmul($binary_code, 10);
+        $binary_code = bcmul($binary_code, strval(10));
         $binary_code = bcadd($binary_code, $tracking_number[0]);
-        $binary_code = bcmul($binary_code, 5);
+        $binary_code = bcmul($binary_code, strval(5));
         $binary_code = bcadd($binary_code, $tracking_number[1]);
         $binary_code .= substr($tracking_number, 2, 18);
 
@@ -360,11 +360,11 @@ public function getBarcode(string $code): Barcode
         // convert binary data to codewords
         $codewords = [];
         $data = $this->hex_to_dec($binary_code_102bit);
-        $codewords[0] = bcmod($data, 636) * 2;
-        $data = bcdiv($data, 636);
+        $codewords[0] = bcmod($data, strval(636)) * 2;
+        $data = bcdiv($data, strval(636));
         for ($i = 1; $i < 9; ++$i) {
-            $codewords[$i] = bcmod($data, 1365);
-            $data = bcdiv($data, 1365);
+            $codewords[$i] = bcmod($data, strval(1365));
+            $data = bcdiv($data, strval(1365));
         }
         $codewords[9] = $data;
         if (($fcs >> 10) == 1) {
@@ -440,7 +440,7 @@ protected function dec_to_hex($number)
         $hex = [];
 
         while ($number > 0) {
-            array_push($hex, strtoupper(dechex(bcmod($number, '16'))));
+            $hex[] = strtoupper(dechex(intval(bcmod(strval($number), '16'))));
             $number = bcdiv($number, '16', 0);
         }
         $hex = array_reverse($hex);
@@ -501,8 +501,8 @@ protected function hex_to_dec($hex)
         $bitval = 1;
         $len = strlen($hex);
         for ($pos = ($len - 1); $pos >= 0; --$pos) {
-            $dec = bcadd($dec, bcmul(hexdec($hex[$pos]), $bitval));
-            $bitval = bcmul($bitval, 16);
+            $dec = bcadd($dec, bcmul(strval(hexdec($hex[$pos])), strval($bitval)));
+            $bitval = bcmul($bitval, '16');
         }
 
         return $dec;
diff --git a/src/Types/TypeInterleaved25Checksum.php b/src/Types/TypeInterleaved25Checksum.php
index 0cb9aa6..5871e9b 100644
--- a/src/Types/TypeInterleaved25Checksum.php
+++ b/src/Types/TypeInterleaved25Checksum.php
@@ -62,7 +62,7 @@ public function getBarcode(string $code): Barcode
                 } else {
                     $t = false; // space
                 }
-                $w = $seq[$j];
+                $w = intval($seq[$j]);
                 $barcode->addBar(new BarcodeBar($w, 1, $t));
             }
         }
diff --git a/src/Types/TypeKix.php b/src/Types/TypeKix.php
index 08595a5..de20cf8 100644
--- a/src/Types/TypeKix.php
+++ b/src/Types/TypeKix.php
@@ -12,5 +12,5 @@
 
 class TypeKix extends TypeRms4cc
 {
-    protected $kix = true;
+    protected bool $kix = true;
 }
diff --git a/src/Types/TypePharmacode.php b/src/Types/TypePharmacode.php
index 66a628b..80b3aee 100644
--- a/src/Types/TypePharmacode.php
+++ b/src/Types/TypePharmacode.php
@@ -31,6 +31,6 @@ public function getBarcode(string $code): Barcode
         $seq = substr($seq, 0, -2);
         $seq = strrev($seq);
 
-        return BinarySequenceConverter::convert($code, $seq);
+        return BinarySequenceConverter::convert(strval($code), $seq);
     }
 }
diff --git a/src/Types/TypePharmacodeTwoCode.php b/src/Types/TypePharmacodeTwoCode.php
index cde23c0..41de30f 100644
--- a/src/Types/TypePharmacodeTwoCode.php
+++ b/src/Types/TypePharmacodeTwoCode.php
@@ -9,7 +9,6 @@
 
 use Picqer\Barcode\Barcode;
 use Picqer\Barcode\BarcodeBar;
-use Picqer\Barcode\Exceptions\BarcodeException;
 use Picqer\Barcode\Exceptions\InvalidCharacterException;
 use Picqer\Barcode\Exceptions\InvalidLengthException;
 
@@ -46,7 +45,7 @@ public function getBarcode(string $code): Barcode
 
         $seq = strrev($seq);
 
-        $barcode = new Barcode($code);
+        $barcode = new Barcode(strval($code));
 
         for ($i = 0; $i < strlen($seq); ++$i) {
             switch ($seq[$i]) {
@@ -69,9 +68,9 @@ public function getBarcode(string $code): Barcode
                     throw new InvalidCharacterException('Could not find bar for char.');
             }
 
-            $barcode->addBar(new BarcodeBar(1, $h, 1, $p));
+            $barcode->addBar(new BarcodeBar(1, $h, true, $p));
             if ($i < (strlen($seq) - 1)) {
-                $barcode->addBar(new BarcodeBar(1, 2, 0, 0));
+                $barcode->addBar(new BarcodeBar(1, 2, false, 0));
             }
         }
 
diff --git a/src/Types/TypePostnet.php b/src/Types/TypePostnet.php
index a43d093..2d136b3 100644
--- a/src/Types/TypePostnet.php
+++ b/src/Types/TypePostnet.php
@@ -49,20 +49,20 @@ public function getBarcode(string $code): Barcode
         $len = strlen($code);
 
         // start bar
-        $barcode->addBar(new BarcodeBar(1, 2, 1));
-        $barcode->addBar(new BarcodeBar(1, 2, 0));
+        $barcode->addBar(new BarcodeBar(1, 2, true));
+        $barcode->addBar(new BarcodeBar(1, 2, false));
 
         for ($i = 0; $i < $len; ++$i) {
             for ($j = 0; $j < 5; ++$j) {
                 $h = $this->barlen[$code[$i]][$j];
-                $p = floor(1 / $h);
-                $barcode->addBar(new BarcodeBar(1, $h, 1, $p));
-                $barcode->addBar(new BarcodeBar(1, 2, 0));
+                $p = (int)floor(1 / $h);
+                $barcode->addBar(new BarcodeBar(1, (int)$h, true, $p));
+                $barcode->addBar(new BarcodeBar(1, 2, false));
             }
         }
 
         // end bar
-        $barcode->addBar(new BarcodeBar(1, 2, 1));
+        $barcode->addBar(new BarcodeBar(1, 2, true));
 
         return $barcode;
     }
diff --git a/src/Types/TypeRms4cc.php b/src/Types/TypeRms4cc.php
index 8dac3b4..684a624 100644
--- a/src/Types/TypeRms4cc.php
+++ b/src/Types/TypeRms4cc.php
@@ -15,7 +15,7 @@
 
 class TypeRms4cc implements TypeInterface
 {
-    protected $kix = false;
+    protected bool $kix = false;
 
     public function getBarcode(string $code): Barcode
     {
@@ -122,8 +122,8 @@ public function getBarcode(string $code): Barcode
             ++$len;
 
             // start bar
-            $barcode->addBar(new BarcodeBar(1, 2, 1));
-            $barcode->addBar(new BarcodeBar(1, 2, 0));
+            $barcode->addBar(new BarcodeBar(1, 2, true));
+            $barcode->addBar(new BarcodeBar(1, 2, false));
         }
 
         for ($i = 0; $i < $len; ++$i) {
@@ -150,14 +150,14 @@ public function getBarcode(string $code): Barcode
                         break;
                 }
 
-                $barcode->addBar(new BarcodeBar(1, $h, 1, $p));
-                $barcode->addBar(new BarcodeBar(1, 2, 0));
+                $barcode->addBar(new BarcodeBar(1, $h, true, $p));
+                $barcode->addBar(new BarcodeBar(1, 2, false));
             }
         }
 
         if (! $this->kix) {
             // stop bar
-            $barcode->addBar(new BarcodeBar(1, 3, 1));
+            $barcode->addBar(new BarcodeBar(1, 3, true));
         }
 
         return $barcode;
diff --git a/src/Types/TypeTelepen.php b/src/Types/TypeTelepen.php
index 6ec1158..378e342 100644
--- a/src/Types/TypeTelepen.php
+++ b/src/Types/TypeTelepen.php
@@ -50,7 +50,7 @@ public function getBarcode(string $code): Barcode
         $drawBar = true;
         for ($i = 0; $i < strlen($encoded); ++$i) {
             $barWidth = $encoded[$i];
-            $barcode->addBar(new BarcodeBar($barWidth, 250, $drawBar));
+            $barcode->addBar(new BarcodeBar(intval($barWidth), 250, $drawBar));
             $drawBar = !$drawBar; //flip to other colour
         }
 
@@ -101,7 +101,7 @@ protected function encodeAlpha($code) : string
             $check_digit = 0;
         }
 
-        $dest .= $this->telepen_lookup_table[ord($check_digit)];
+        $dest .= $this->telepen_lookup_table[ord(strval($check_digit))];
         $dest .= $this->telepen_lookup_table[ord(self::TELEPEN_STOP_CHAR)]; // Stop
 
         return $dest;