diff -u b/viewsreference.install b/viewsreference.install
--- b/viewsreference.install
+++ b/viewsreference.install
@@ -113,14 +113,14 @@
             $row_data = $existing_data[$_table][$stack_id];
             // Data can empty because it was for advanced use.
             // phpcs:disable DrupalPractice.FunctionCalls.InsecureUnserialize.InsecureUnserialize
-            $existing_data_row = is_string($row_data["${field_name}_data"]) ? unserialize($row_data["${field_name}_data"], ['allowed_class' => FALSE]) : [];
+            $existing_data_row = is_string($row_data["{$field_name}_data"]) ? unserialize($row_data["{$field_name}_data"], ['allowed_class' => FALSE]) : [];
             // phpcs:enable
-            $existing_data_row['title'] = $row_data["${field_name}_title"];
-            $existing_data_row['argument'] = $row_data["${field_name}_argument"];
-            $existing_data[$_table][$stack_id]["${field_name}_data"] = serialize(array_filter($existing_data_row));
+            $existing_data_row['title'] = $row_data["{$field_name}_title"];
+            $existing_data_row['argument'] = $row_data["{$field_name}_argument"];
+            $existing_data[$_table][$stack_id]["{$field_name}_data"] = serialize(array_filter($existing_data_row));
             unset(
-              $existing_data[$_table][$stack_id]["${field_name}_argument"],
-              $existing_data[$_table][$stack_id]["${field_name}_title"]
+              $existing_data[$_table][$stack_id]["{$field_name}_argument"],
+              $existing_data[$_table][$stack_id]["{$field_name}_title"]
             );
             if (!$did_fields) {
               $did_fields = TRUE;
@@ -133,8 +133,8 @@
         }
 
         // Drop existing argument and title fields.
-        $database->schema()->dropField($_table, "${field_name}_argument");
-        $database->schema()->dropField($_table, "${field_name}_title");
+        $database->schema()->dropField($_table, "{$field_name}_argument");
+        $database->schema()->dropField($_table, "{$field_name}_title");
       }
 
       // Update field definition settings to enable the title/argument plugins.