diff --git a/src/Decoder/IMagickLuminanceSource.php b/src/Decoder/IMagickLuminanceSource.php
index edf8a3975..cfb307173 100644
--- a/src/Decoder/IMagickLuminanceSource.php
+++ b/src/Decoder/IMagickLuminanceSource.php
@@ -51,7 +51,7 @@ final class IMagickLuminanceSource extends LuminanceSourceAbstract{
 
 		if($this->options->readerIncreaseContrast){
 			for($i = 0; $i < 10; $i++){
-				$this->imagick->contrastImage(0);
+				$this->imagick->contrastImage(false); // misleading docs
 			}
 		}
 
diff --git a/tests/QRCodeReaderTest.php b/tests/QRCodeReaderTest.php
index 5d396b743..6f9567883 100644
--- a/tests/QRCodeReaderTest.php
+++ b/tests/QRCodeReaderTest.php
@@ -19,7 +19,6 @@ use chillerlan\QRCode\{QRCode, QROptions};
 use chillerlan\QRCode\Decoder\{GDLuminanceSource, IMagickLuminanceSource};
 use PHPUnit\Framework\TestCase;
 use function extension_loaded, range, sprintf, str_repeat, substr;
-use const PHP_OS_FAMILY, PHP_VERSION_ID;
 
 /**
  * Tests the QR Code reader