diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument/ArgumentPluginBase.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument/ArgumentPluginBase.php
index a015395f5a57d9e46b73a02138e172c201a27df4..66177c2fe117fcbf0d4701c33a718119cf56e2f8 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument/ArgumentPluginBase.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument/ArgumentPluginBase.php
@@ -884,7 +884,7 @@ public function summarySort($order, $by = NULL) {
    * @param $data
    *   The query results for the row.
    */
-  function summary_argument($data) {
+ public function summaryArgument($data) {
     return $data->{$this->base_alias};
   }
 
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument/DayDate.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument/DayDate.php
index 861270384b7511d4308c081ed48236ec4b3a19ad..c06a149c33e793843bee5c54a81c6823ee5098f4 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument/DayDate.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument/DayDate.php
@@ -43,7 +43,7 @@ function title() {
     return format_date(strtotime("2005" . "05" . $day . " 00:00:00 UTC"), 'custom', $this->format, 'UTC');
   }
 
-  function summary_argument($data) {
+  public function summaryArgument($data) {
     // Make sure the argument contains leading zeroes.
     return str_pad($data->{$this->base_alias}, 2, '0', STR_PAD_LEFT);
   }
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument/Formula.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument/Formula.php
index 89adc6b7ce8004d8d16961a84308d84ce9670324..e74ae6fe1e6c01d37ab448671663fe5ed0b27397 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument/Formula.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument/Formula.php
@@ -14,7 +14,7 @@
 /**
  * Abstract argument handler for simple formulae.
  *
- * Child classes of this object should implement summary_argument, at least.
+ * Child classes of this object should implement summaryArgument, at least.
  *
  * Definition terms:
  * - formula: The formula to use for this handler.
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument/ManyToOne.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument/ManyToOne.php
index 6074790f30f0818fe5d8556fde44451ee6c8c9b1..c89cd0ba437b954857dc6e2775b70de7352f59a0 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument/ManyToOne.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument/ManyToOne.php
@@ -184,7 +184,7 @@ function summary_query() {
     return $this->summaryBasics();
   }
 
-  function summary_argument($data) {
+  public function summaryArgument($data) {
     $value = $data->{$this->base_alias};
     if (empty($value)) {
       $value = 0;
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument/MonthDate.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument/MonthDate.php
index 1981157efb0fe95cc49bee69efa4770dc2ce8077..2283c4cac84e9872a121c0202e8bdfa22a5ec9fe 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument/MonthDate.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument/MonthDate.php
@@ -42,7 +42,7 @@ function title() {
     return format_date(strtotime("2005" . $month . "15" . " 00:00:00 UTC"), 'custom', $this->format, 'UTC');
   }
 
-  function summary_argument($data) {
+  public function summaryArgument($data) {
     // Make sure the argument contains leading zeroes.
     return str_pad($data->{$this->base_alias}, 2, '0', STR_PAD_LEFT);
   }
diff --git a/core/modules/views/lib/Drupal/views/Plugin/views/argument/String.php b/core/modules/views/lib/Drupal/views/Plugin/views/argument/String.php
index 44bde0d54bb44068dfc9b7b29d34f6d1059c8e55..cae4bb42aae5264f4e2b78c261a8e5bf30844e40 100644
--- a/core/modules/views/lib/Drupal/views/Plugin/views/argument/String.php
+++ b/core/modules/views/lib/Drupal/views/Plugin/views/argument/String.php
@@ -241,7 +241,7 @@ public function query($group_by = FALSE) {
     }
   }
 
-  function summary_argument($data) {
+  public function summaryArgument($data) {
     $value = $this->caseTransform($data->{$this->base_alias}, $this->options['path_case']);
     if (!empty($this->options['transform_dash'])) {
       $value = strtr($value, ' ', '-');
diff --git a/core/modules/views/views.theme.inc b/core/modules/views/views.theme.inc
index 680702a6e29b0e321f3bfe6eec88327687c3a8fa..40ff1d5c2e153dc169f5b2ba7fe55ac3835356ce 100644
--- a/core/modules/views/views.theme.inc
+++ b/core/modules/views/views.theme.inc
@@ -433,7 +433,7 @@ function template_preprocess_views_view_summary(&$vars) {
   $row_args = array();
 
   foreach ($vars['rows'] as $id => $row) {
-    $row_args[$id] = $argument->summary_argument($row);
+    $row_args[$id] = $argument->summaryArgument($row);
   }
   $argument->process_summary_arguments($row_args);
 
@@ -493,7 +493,7 @@ function template_preprocess_views_view_summary_unformatted(&$vars) {
   // this could cause performance problems.
   $row_args = array();
   foreach ($vars['rows'] as $id => $row) {
-    $row_args[$id] = $argument->summary_argument($row);
+    $row_args[$id] = $argument->summaryArgument($row);
   }
   $argument->process_summary_arguments($row_args);