diff --git a/search_api.module b/search_api.module
index e97d9ef..e50774d 100644
--- a/search_api.module
+++ b/search_api.module
@@ -84,7 +84,7 @@ function search_api_cron() {
           // Therefore, don't index for any index on this server.
           $ignored_servers[$index->getServerId()] = TRUE;
           $vars['%index'] = $index->label();
-          watchdog_exception('search_api', $e, '%type while trying to index items on %index: !message in %function (line %line of %file).', $vars);
+          watchdog_exception('search_api', $e, '%type while trying to index items on %index: @message in %function (line %line of %file).', $vars);
         }
       }
       if (!$num) {
diff --git a/search_api_db/src/Plugin/search_api/backend/Database.php b/search_api_db/src/Plugin/search_api/backend/Database.php
index 538c20f..67370fc 100644
--- a/search_api_db/src/Plugin/search_api/backend/Database.php
+++ b/search_api_db/src/Plugin/search_api/backend/Database.php
@@ -831,7 +831,7 @@ class Database extends BackendPluginBase {
         }
         catch (\PDOException $e) {
           $vars['%index'] = $index->label();
-          watchdog_exception('search_api_db', $e, '%type while trying to change collation for the fulltext table of index %index: !message in %function (line %line of %file).', $vars);
+          watchdog_exception('search_api_db', $e, '%type while trying to change collation for the fulltext table of index %index: @message in %function (line %line of %file).', $vars);
         }
       }
 
diff --git a/src/Backend/BackendPluginBase.php b/src/Backend/BackendPluginBase.php
index c564552..dad1304 100644
--- a/src/Backend/BackendPluginBase.php
+++ b/src/Backend/BackendPluginBase.php
@@ -132,7 +132,7 @@ abstract class BackendPluginBase extends ConfigurablePluginBase implements Backe
       $vars = array(
         '%server' => $this->getServer()->label(),
       );
-      watchdog_exception('search_api', $e, '%type while deleting items from server %server: !message in %function (line %line of %file).', $vars);
+      watchdog_exception('search_api', $e, '%type while deleting items from server %server: @message in %function (line %line of %file).', $vars);
       drupal_set_message($this->t('Deleting some of the items on the server failed. Check the logs for details. The server was still removed.'), 'error');
     }
   }
diff --git a/src/Entity/Index.php b/src/Entity/Index.php
index ec51026..3c7a871 100644
--- a/src/Entity/Index.php
+++ b/src/Entity/Index.php
@@ -624,7 +624,7 @@ class Index extends ConfigEntityBase implements IndexInterface {
         }
         catch (SearchApiException $e) {
           $variables['%index'] = $this->label();
-          watchdog_exception('search_api', $e, '%type while retrieving fields for index %index: !message in %function (line %line of %file).', $variables);
+          watchdog_exception('search_api', $e, '%type while retrieving fields for index %index: @message in %function (line %line of %file).', $variables);
         }
       }
       if ($this->unmappedFields) {
@@ -980,7 +980,7 @@ class Index extends ConfigEntityBase implements IndexInterface {
         }
         catch (SearchApiException $e) {
           $variables['%index'] = $this->label();
-          watchdog_exception('search_api', $e, '%type while trying to index items on index %index: !message in %function (line %line of %file)', $variables);
+          watchdog_exception('search_api', $e, '%type while trying to index items on index %index: @message in %function (line %line of %file)', $variables);
         }
       }
     }
diff --git a/src/Entity/Server.php b/src/Entity/Server.php
index 11d4286..e737946 100644
--- a/src/Entity/Server.php
+++ b/src/Entity/Server.php
@@ -203,7 +203,7 @@ class Server extends ConfigEntityBase implements ServerInterface {
         '%server' => $this->label(),
         '%index' => $index->label(),
       );
-      watchdog_exception('search_api', $e, '%type while adding index %index to server %server: !message in %function (line %line of %file).', $vars);
+      watchdog_exception('search_api', $e, '%type while adding index %index to server %server: @message in %function (line %line of %file).', $vars);
       $server_task_manager->add($this, __FUNCTION__, $index);
     }
   }
@@ -224,7 +224,7 @@ class Server extends ConfigEntityBase implements ServerInterface {
         '%server' => $this->label(),
         '%index' => $index->label(),
       );
-      watchdog_exception('search_api', $e, '%type while updating the fields of index %index on server %server: !message in %function (line %line of %file).', $vars);
+      watchdog_exception('search_api', $e, '%type while updating the fields of index %index on server %server: @message in %function (line %line of %file).', $vars);
     }
     $server_task_manager->add($this, __FUNCTION__, $index, isset($index->original) ? $index->original : NULL);
   }
@@ -246,7 +246,7 @@ class Server extends ConfigEntityBase implements ServerInterface {
         '%server' => $this->label(),
         '%index' => is_object($index) ? $index->label() : $index,
       );
-      watchdog_exception('search_api', $e, '%type while removing index %index from server %server: !message in %function (line %line of %file).', $vars);
+      watchdog_exception('search_api', $e, '%type while removing index %index from server %server: @message in %function (line %line of %file).', $vars);
       $server_task_manager->add($this, __FUNCTION__, $index);
     }
   }
@@ -286,7 +286,7 @@ class Server extends ConfigEntityBase implements ServerInterface {
       $vars = array(
         '%server' => $this->label(),
       );
-      watchdog_exception('search_api', $e, '%type while deleting items from server %server: !message in %function (line %line of %file).', $vars);
+      watchdog_exception('search_api', $e, '%type while deleting items from server %server: @message in %function (line %line of %file).', $vars);
     }
     $server_task_manager->add($this, __FUNCTION__, $index, $item_ids);
   }
@@ -315,7 +315,7 @@ class Server extends ConfigEntityBase implements ServerInterface {
         '%server' => $this->label(),
         '%index' => $index->label(),
       );
-      watchdog_exception('search_api', $e, '%type while deleting items of index %index from server %server: !message in %function (line %line of %file).', $vars);
+      watchdog_exception('search_api', $e, '%type while deleting items of index %index from server %server: @message in %function (line %line of %file).', $vars);
     }
     $server_task_manager->add($this, __FUNCTION__, $index);
   }
@@ -335,7 +335,7 @@ class Server extends ConfigEntityBase implements ServerInterface {
         $args = array(
           '%index' => $index->label(),
         );
-        watchdog_exception('search_api', $e, '%type while deleting all items from index %index: !message in %function (line %line of %file).', $args);
+        watchdog_exception('search_api', $e, '%type while deleting all items from index %index: @message in %function (line %line of %file).', $args);
         $failed[] = $index->label();
       }
     }
diff --git a/src/Form/IndexClearConfirmForm.php b/src/Form/IndexClearConfirmForm.php
index 785e04c..238ef55 100644
--- a/src/Form/IndexClearConfirmForm.php
+++ b/src/Form/IndexClearConfirmForm.php
@@ -50,7 +50,7 @@ class IndexClearConfirmForm extends EntityConfirmFormBase {
     }
     catch (SearchApiException $e) {
       drupal_set_message($this->t('Failed to clear the search index %name.', array('%name' => $entity->label())), 'error');
-      watchdog_exception('search_api', $e, '%type while trying to clear the index %name: !message in %function (line %line of %file)', array('%name' => $entity->label()));
+      watchdog_exception('search_api', $e, '%type while trying to clear the index %name: @message in %function (line %line of %file)', array('%name' => $entity->label()));
     }
 
     $form_state->setRedirect('entity.search_api_index.canonical', array('search_api_index' => $entity->id()));
diff --git a/src/Form/IndexReindexConfirmForm.php b/src/Form/IndexReindexConfirmForm.php
index ad29569..944b6d1 100644
--- a/src/Form/IndexReindexConfirmForm.php
+++ b/src/Form/IndexReindexConfirmForm.php
@@ -51,7 +51,7 @@ class IndexReindexConfirmForm extends EntityConfirmFormBase {
     }
     catch (SearchApiException $e) {
       drupal_set_message($this->t('Failed to reindex items for the search index %name.', array('%name' => $entity->label())), 'error');
-      watchdog_exception('search_api', $e, '%type while trying to reindex items on index %name: !message in %function (line %line of %file)', array('%name' => $entity->label()));
+      watchdog_exception('search_api', $e, '%type while trying to reindex items on index %name: @message in %function (line %line of %file)', array('%name' => $entity->label()));
     }
 
     $form_state->setRedirect('entity.search_api_index.canonical', array('search_api_index' => $entity->id()));
diff --git a/src/Form/ServerClearConfirmForm.php b/src/Form/ServerClearConfirmForm.php
index 96b8cdb..c356e98 100644
--- a/src/Form/ServerClearConfirmForm.php
+++ b/src/Form/ServerClearConfirmForm.php
@@ -66,7 +66,7 @@ class ServerClearConfirmForm extends EntityConfirmFormBase {
         $args = array(
           '%index' => $index->label(),
         );
-        watchdog_exception('search_api', $e, '%type while clearing index %index: !message in %function (line %line of %file).', $args);
+        watchdog_exception('search_api', $e, '%type while clearing index %index: @message in %function (line %line of %file).', $args);
         $failed_reindexing[] = $index->label();
       }
     }