diff -u b/README.md b/README.md
--- b/README.md
+++ b/README.md
@@ -28,8 +28,8 @@
 -----------------|----------------------------------------------------------------------------------------------|:----------:|:-------------------:|
 Auto orientation | Uses EXIF Orientation tags to determine the image orientation.                               | X          | X                   |
 Brightness       | Supports changing brightness settings of an image. Also supports negative values (darkening).| X          | X                   |
-Contrast         | Supports changing contrast settings of an image. Also supports negative values.              | X          | X                   |
 Color shift      | Colorizes image.                                                                             | X          | X                   |
+Contrast         | Supports changing contrast settings of an image. Also supports negative values.              | X          | X                   |
 Strip metadata   | Strips all EXIF metadata from image.                                                         | X          | X                   |
 Watermark        | Place a image with transparency anywhere over a source picture.                              | X          | X                   |
 
diff -u b/src/Plugin/ImageEffect/ContrastImageEffect.php b/src/Plugin/ImageEffect/ContrastImageEffect.php
--- b/src/Plugin/ImageEffect/ContrastImageEffect.php
+++ b/src/Plugin/ImageEffect/ContrastImageEffect.php
@@ -51,8 +51,8 @@
       '#title' => $this->t('Contrast'),
       '#description'  => $this->t('The contrast effect enhances the intensity differences between the lighter and darker elements of the image.'),
       '#default_value' => $this->configuration['level'],
-      '#field_prefix' => ' ' . t('±'),
-      '#field_suffix' => ' ' . t('%'),
+      '#field_prefix' => $this->t('±'),
+      '#field_suffix' => $this->t('%'),
       '#required' => TRUE,
       '#size' => 5,
       '#min' => -100,
only in patch2:
unchanged:
--- a/src/Plugin/ImageEffect/BrightnessImageEffect.php
+++ b/src/Plugin/ImageEffect/BrightnessImageEffect.php
@@ -51,8 +51,8 @@ class BrightnessImageEffect extends ConfigurableImageEffectBase implements Conta
       '#title' => $this->t('Brightness'),
       '#description'  => $this->t('The brightness effect seldom looks good on its own, but can be useful to wash out an image before making it transparent - e.g. for a watermark.'),
       '#default_value' => $this->configuration['level'],
-      '#field_prefix' => ' ' . t('±'),
-      '#field_suffix' => ' ' . t('%'),
+      '#field_prefix' => $this->t('±'),
+      '#field_suffix' => $this->t('%'),
       '#required' => TRUE,
       '#size' => 5,
       '#min' => -100,