diff --git a/src/Form/Type/ExponentialNumberType.php b/src/Form/Type/ExponentialNumberType.php
index b76196d9..f566afbb 100644
--- a/src/Form/Type/ExponentialNumberType.php
+++ b/src/Form/Type/ExponentialNumberType.php
@@ -39,7 +39,7 @@ class ExponentialNumberType extends AbstractType
         return NumberType::class;
     }
 
-    public function configureOptions(OptionsResolver $resolver)
+    public function configureOptions(OptionsResolver $resolver): void
     {
         $resolver->setDefaults([
             //We want to allow the full precision of the number, so disable rounding
@@ -47,7 +47,7 @@ class ExponentialNumberType extends AbstractType
         ]);
     }
 
-    public function buildForm(FormBuilderInterface $builder, array $options)
+    public function buildForm(FormBuilderInterface $builder, array $options): void
     {
         $builder->resetViewTransformers();