diff --git a/code/Model/EditableFormField/EditableFileField.php b/code/Model/EditableFormField/EditableFileField.php
index da2ffd88..0b9c7828 100755
--- a/code/Model/EditableFormField/EditableFileField.php
+++ b/code/Model/EditableFormField/EditableFileField.php
@@ -179,10 +179,7 @@ public function getCMSFields()
         return parent::getCMSFields();
     }
 
-    /**
-     * @return ValidationResult
-     */
-    public function validate()
+    public function validate(): ValidationResult
     {
         $result = parent::validate();
 
diff --git a/code/Model/EditableFormField/EditableNumericField.php b/code/Model/EditableFormField/EditableNumericField.php
index aa754842..1cf6d592 100755
--- a/code/Model/EditableFormField/EditableNumericField.php
+++ b/code/Model/EditableFormField/EditableNumericField.php
@@ -7,6 +7,7 @@
 use SilverStripe\Forms\LiteralField;
 use SilverStripe\Forms\NumericField;
 use SilverStripe\UserForms\Model\EditableFormField;
+use SilverStripe\Core\Validation\ValidationResult;
 
 /**
  * EditableNumericField
@@ -85,7 +86,7 @@ protected function updateFormField($field)
         }
     }
 
-    public function validate()
+    public function validate(): ValidationResult
     {
         $result = parent::validate();
         if ($this->MinValue > $this->MaxValue) {
diff --git a/code/Model/EditableFormField/EditableTextField.php b/code/Model/EditableFormField/EditableTextField.php
index 09d33a84..dc8a3d0e 100644
--- a/code/Model/EditableFormField/EditableTextField.php
+++ b/code/Model/EditableFormField/EditableTextField.php
@@ -105,10 +105,7 @@ public function getCMSFields()
         return parent::getCMSFields();
     }
 
-    /**
-     * @return ValidationResult
-     */
-    public function validate()
+    public function validate(): ValidationResult
     {
         $result = parent::validate();
 
diff --git a/code/Model/Recipient/EmailRecipient.php b/code/Model/Recipient/EmailRecipient.php
index b7540b44..0d339b48 100644
--- a/code/Model/Recipient/EmailRecipient.php
+++ b/code/Model/Recipient/EmailRecipient.php
@@ -603,10 +603,8 @@ public function getEmailTemplateDropdownValues()
 
     /**
      * Validate that valid email addresses are being used
-     *
-     * @return ValidationResult
      */
-    public function validate()
+    public function validate(): ValidationResult
     {
         $result = parent::validate();
         $checkEmail = [