diff --git a/src/Plugin/EntityPrint/PrintEngine/PhpWkhtmlToPdf.php b/src/Plugin/EntityPrint/PrintEngine/PhpWkhtmlToPdf.php
index 820d0d2..19b063b 100644
--- a/src/Plugin/EntityPrint/PrintEngine/PhpWkhtmlToPdf.php
+++ b/src/Plugin/EntityPrint/PrintEngine/PhpWkhtmlToPdf.php
@@ -128,6 +128,7 @@ class PhpWkhtmlToPdf extends PdfEngineBase implements AlignableHeaderFooterInter
       '#description' => $this->t('Set this to zoom the pages - needed to produce hairlines.'),
       '#default_value' => $this->configuration['zoom'],
       '#weight' => -8,
+      '#step' => 0.01
     ];
 
     $form['binary_location'] = [