diff --git a/Extension/Core/DataTransformer/DateTimeToLocalizedStringTransformer.php b/Extension/Core/DataTransformer/DateTimeToLocalizedStringTransformer.php
index 6ca20106fa..9b5e4f4f5a 100644
--- a/Extension/Core/DataTransformer/DateTimeToLocalizedStringTransformer.php
+++ b/Extension/Core/DataTransformer/DateTimeToLocalizedStringTransformer.php
@@ -136,7 +136,7 @@ public function reverseTransform($value)
                 $dateTime = new \DateTime(sprintf('@%s', $timestamp));
             }
             // set timezone separately, as it would be ignored if set via the constructor,
-            // see http://php.net/manual/en/datetime.construct.php
+            // see https://php.net/datetime.construct
             $dateTime->setTimezone(new \DateTimeZone($this->outputTimezone));
         } catch (\Exception $e) {
             throw new TransformationFailedException($e->getMessage(), $e->getCode(), $e);
@@ -169,7 +169,7 @@ protected function getIntlDateFormatter($ignoreTimezone = false)
 
         $intlDateFormatter = new \IntlDateFormatter(\Locale::getDefault(), $dateFormat, $timeFormat, $timezone, $calendar, $pattern);
 
-        // new \intlDateFormatter may return null instead of false in case of failure, see https://bugs.php.net/bug.php?id=66323
+        // new \intlDateFormatter may return null instead of false in case of failure, see https://bugs.php.net/66323
         if (!$intlDateFormatter) {
             throw new TransformationFailedException(intl_get_error_message(), intl_get_error_code());
         }
diff --git a/Extension/Core/DataTransformer/DateTimeToStringTransformer.php b/Extension/Core/DataTransformer/DateTimeToStringTransformer.php
index 55501298b2..cb4b4db733 100644
--- a/Extension/Core/DataTransformer/DateTimeToStringTransformer.php
+++ b/Extension/Core/DataTransformer/DateTimeToStringTransformer.php
@@ -57,7 +57,7 @@ public function __construct($inputTimezone = null, $outputTimezone = null, $form
 
         $this->generateFormat = $this->parseFormat = $format;
 
-        // See http://php.net/manual/en/datetime.createfromformat.php
+        // See https://php.net/datetime.createfromformat
         // The character "|" in the format makes sure that the parts of a date
         // that are *not* specified in the format are reset to the corresponding
         // values from 1970-01-01 00:00:00 instead of the current time.
diff --git a/Extension/Core/Type/BaseType.php b/Extension/Core/Type/BaseType.php
index 32825ab7af..05d215f63c 100644
--- a/Extension/Core/Type/BaseType.php
+++ b/Extension/Core/Type/BaseType.php
@@ -71,7 +71,7 @@ public function buildView(FormView $view, FormInterface $form, array $options)
 
             // Strip leading underscores and digits. These are allowed in
             // form names, but not in HTML4 ID attributes.
-            // http://www.w3.org/TR/html401/struct/global.html#adef-id
+            // https://www.w3.org/TR/html401/struct/global#adef-id
             $id = ltrim($id, '_0123456789');
         }
 
diff --git a/Extension/Core/Type/DateType.php b/Extension/Core/Type/DateType.php
index 8ab5e9cc8a..464c262c13 100644
--- a/Extension/Core/Type/DateType.php
+++ b/Extension/Core/Type/DateType.php
@@ -107,13 +107,13 @@ public function buildForm(FormBuilderInterface $builder, array $options)
                 \Locale::getDefault(),
                 $dateFormat,
                 $timeFormat,
-                // see https://bugs.php.net/bug.php?id=66323
+                // see https://bugs.php.net/66323
                 class_exists('IntlTimeZone', false) ? \IntlTimeZone::createDefault() : null,
                 $calendar,
                 $pattern
             );
 
-            // new \IntlDateFormatter may return null instead of false in case of failure, see https://bugs.php.net/bug.php?id=66323
+            // new \IntlDateFormatter may return null instead of false in case of failure, see https://bugs.php.net/66323
             if (!$formatter) {
                 throw new InvalidOptionsException(intl_get_error_message(), intl_get_error_code());
             }