diff --git a/src/MySqlEventStore.php b/src/MySqlEventStore.php
index ac74786a..533717cc 100644
--- a/src/MySqlEventStore.php
+++ b/src/MySqlEventStore.php
@@ -283,7 +283,7 @@ public function load(
             $values[$parameter] = $value;
         }
 
-        $where[] = "`no` >= :fromNumber";
+        $where[] = '`no` >= :fromNumber';
 
         $whereCondition = implode(' AND ', $where);
         $limit = min($count, $this->loadBatchSize);
@@ -358,7 +358,7 @@ public function loadReverse(
             $values[$parameter] = $value;
         }
 
-        $where[] = "`no` <= :fromNumber";
+        $where[] = '`no` <= :fromNumber';
 
         $whereCondition = implode(' AND ', $where);
         $limit = min($count, $this->loadBatchSize);
diff --git a/src/PostgresEventStore.php b/src/PostgresEventStore.php
index f5fd08fd..bb280571 100644
--- a/src/PostgresEventStore.php
+++ b/src/PostgresEventStore.php
@@ -252,7 +252,7 @@ public function load(
             $values[$parameter] = $value;
         }
 
-        $where[] = "no >= :fromNumber";
+        $where[] = 'no >= :fromNumber';
 
         $whereCondition = implode(' AND ', $where);
         $limit = min($count, $this->loadBatchSize);
@@ -327,7 +327,7 @@ public function loadReverse(
             $values[$parameter] = $value;
         }
 
-        $where[] = "no <= :fromNumber";
+        $where[] = 'no <= :fromNumber';
 
         $whereCondition = implode(' AND ', $where);
         $limit = min($count, $this->loadBatchSize);