diff --git a/src/Database/Adapter/MariaDB.php b/src/Database/Adapter/MariaDB.php
index 6d2aac8ef..59152a055 100644
--- a/src/Database/Adapter/MariaDB.php
+++ b/src/Database/Adapter/MariaDB.php
@@ -1228,13 +1228,15 @@ public function increaseDocumentAttribute(
         $name = $this->filter($collection);
         $attribute = $this->filter($attribute);
 
-        $sqlMax = $max !== null ? " AND `{$attribute}` <= :max" : '';
-        $sqlMin = $min !== null ? " AND `{$attribute}` >= :min" : '';
+        // A NULL counter (e.g. a column added to a table with existing rows) counts as 0, so it can
+        // be incremented and checked against its bounds instead of staying NULL forever.
+        $sqlMax = $max !== null ? " AND COALESCE(`{$attribute}`, 0) <= :max" : '';
+        $sqlMin = $min !== null ? " AND COALESCE(`{$attribute}`, 0) >= :min" : '';
 
         $sql = "
 			UPDATE {$this->getSQLTable($name)}
 			SET
-			    `{$attribute}` = `{$attribute}` + :val,
+			    `{$attribute}` = COALESCE(`{$attribute}`, 0) + :val,
 			    `_updatedAt` = :updatedAt
 			WHERE _uid = :_uid
 			{$this->getTenantQuery($collection)}
diff --git a/src/Database/Adapter/Mongo.php b/src/Database/Adapter/Mongo.php
index 760e9e79c..f1b8cbe3c 100644
--- a/src/Database/Adapter/Mongo.php
+++ b/src/Database/Adapter/Mongo.php
@@ -2338,9 +2338,18 @@ public function increaseDocumentAttribute(string $collection, string $id, string
         }
 
         $options = $this->getTransactionOptions();
+        $namespace = $this->getNamespace() . '_' . $this->filter($collection);
         try {
+            // $inc refuses a null field, and a null never matches the bounds: a null counter (e.g. an
+            // attribute added after the document was written) counts as 0, as in the SQL adapters.
+            $nullFilters = ['_uid' => $id, $attribute => null];
+            if ($this->sharedTables) {
+                $nullFilters['_tenant'] = $this->getTenantFilters($collection);
+            }
+            $this->client->update($namespace, $nullFilters, ['$set' => [$attribute => 0]], options: $options);
+
             $this->client->update(
-                $this->getNamespace() . '_' . $this->filter($collection),
+                $namespace,
                 $filters,
                 [
                     '$inc' => [$attribute => $value],
diff --git a/src/Database/Adapter/Postgres.php b/src/Database/Adapter/Postgres.php
index 3004e9780..2d820d488 100644
--- a/src/Database/Adapter/Postgres.php
+++ b/src/Database/Adapter/Postgres.php
@@ -1347,13 +1347,15 @@ public function increaseDocumentAttribute(string $collection, string $id, string
         $name = $this->filter($collection);
         $attribute = $this->filter($attribute);
 
-        $sqlMax = $max !== null ? " AND \"{$attribute}\" <= :max" : "";
-        $sqlMin = $min !== null ? " AND \"{$attribute}\" >= :min" : "";
+        // A NULL counter (e.g. a column added to a table with existing rows) counts as 0, so it can
+        // be incremented and checked against its bounds instead of staying NULL forever.
+        $sqlMax = $max !== null ? " AND COALESCE(\"{$attribute}\", 0) <= :max" : "";
+        $sqlMin = $min !== null ? " AND COALESCE(\"{$attribute}\", 0) >= :min" : "";
 
         $sql = "
 			UPDATE {$this->getSQLTable($name)}
 			SET
-			    \"{$attribute}\" = \"{$attribute}\" + :val,
+			    \"{$attribute}\" = COALESCE(\"{$attribute}\", 0) + :val,
                 \"_updatedAt\" = :updatedAt
 			WHERE _uid = :_uid
 			{$this->getTenantQuery($collection)}
diff --git a/tests/e2e/Adapter/Scopes/DocumentTests.php b/tests/e2e/Adapter/Scopes/DocumentTests.php
index 2b6d37822..82ffd4cbe 100644
--- a/tests/e2e/Adapter/Scopes/DocumentTests.php
+++ b/tests/e2e/Adapter/Scopes/DocumentTests.php
@@ -2189,6 +2189,39 @@ public function testIncreaseDecrease(): Document
         return $document;
     }
 
+    public function testIncreaseDecreaseAttributeAddedAfterDocument(): void
+    {
+        /** @var Database $database */
+        $database = $this->getDatabase();
+
+        $collection = 'increase_decrease_added_attribute';
+        $database->createCollection($collection);
+        $this->assertEquals(true, $database->createAttribute($collection, 'name', Database::VAR_STRING, 64, false));
+
+        $document = $database->createDocument($collection, new Document([
+            'name' => 'existing',
+            '$permissions' => [
+                Permission::read(Role::any()),
+                Permission::update(Role::any()),
+            ],
+        ]));
+
+        // Added once the document exists: its stored value is NULL, not the default.
+        $this->assertEquals(true, $database->createAttribute($collection, 'counter', Database::VAR_INTEGER, 0, false, 0));
+
+        $doc = $database->increaseDocumentAttribute($collection, $document->getId(), 'counter', 1);
+        $this->assertEquals(1, $doc->getAttribute('counter'));
+        $this->assertEquals(1, $database->getDocument($collection, $document->getId())->getAttribute('counter'));
+
+        $database->increaseDocumentAttribute($collection, $document->getId(), 'counter', 2, 10);
+        $this->assertEquals(3, $database->getDocument($collection, $document->getId())->getAttribute('counter'));
+
+        $database->decreaseDocumentAttribute($collection, $document->getId(), 'counter', 1, 0);
+        $this->assertEquals(2, $database->getDocument($collection, $document->getId())->getAttribute('counter'));
+
+        $database->deleteCollection($collection);
+    }
+
     public function testCreateUpdateBigIntAndIncrementDecrement(): void
     {
         /** @var Database $database */