diff --git a/Flow/Extractor/SpoutSheetExtractor.php b/Flow/Extractor/SpoutSheetExtractor.php
index 27d5bc0..8027e71 100644
--- a/Flow/Extractor/SpoutSheetExtractor.php
+++ b/Flow/Extractor/SpoutSheetExtractor.php
@@ -35,14 +35,14 @@ public function extract(): \Generator
 
         $this->skipLines($iterator, $this->skipLines);
 
-        $columns = $iterator->current();
+        $columns = $iterator->current()->toArray();
         $columnCount = count($columns);
 
         $iterator->next();
 
         $currentLine = $this->skipLines + 1;
         while ($iterator->valid()) {
-            $line = $iterator->current();
+            $line = $iterator->current()->toArray();
             $cellCount = count($line);
 
             if ($columnCount < $cellCount) {
diff --git a/composer.json b/composer.json
index 002eb30..a6f2ca7 100644
--- a/composer.json
+++ b/composer.json
@@ -17,7 +17,7 @@
         "phpunit/phpunit": "6.5.*",
         "johnkary/phpunit-speedtrap": "^2.0",
         "mybuilder/phpunit-accelerator": "^2.0",
-        "box/spout": "^2.7",
+        "box/spout": "^3.1",
         "symfony/serializer": "^3.4 || ^4.0",
         "monolog/monolog": "^1.24"
     },
diff --git a/composer.lock b/composer.lock
index 70e1490..0b3d0c2 100644
--- a/composer.lock
+++ b/composer.lock
@@ -1,10 +1,10 @@
 {
     "_readme": [
         "This file locks the dependencies of your project to a known state",
-        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
+        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "925803c97d9ccaff58aed2be9b28d167",
+    "content-hash": "98aa052715c78c287f8417bedd1da11f",
     "packages": [
         {
             "name": "nikic/php-parser",
@@ -61,25 +61,27 @@
     "packages-dev": [
         {
             "name": "box/spout",
-            "version": "v2.7.3",
+            "version": "v3.3.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/box/spout.git",
-                "reference": "3681a3421a868ab9a65da156c554f756541f452b"
+                "reference": "9bdb027d312b732515b884a341c0ad70372c6295"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/box/spout/zipball/3681a3421a868ab9a65da156c554f756541f452b",
-                "reference": "3681a3421a868ab9a65da156c554f756541f452b",
+                "url": "https://api.github.com/repos/box/spout/zipball/9bdb027d312b732515b884a341c0ad70372c6295",
+                "reference": "9bdb027d312b732515b884a341c0ad70372c6295",
                 "shasum": ""
             },
             "require": {
+                "ext-dom": "*",
                 "ext-xmlreader": "*",
                 "ext-zip": "*",
-                "php": ">=5.4.0"
+                "php": ">=7.2.0"
             },
             "require-dev": {
-                "phpunit/phpunit": "^4.8.0"
+                "friendsofphp/php-cs-fixer": "^2",
+                "phpunit/phpunit": "^8"
             },
             "suggest": {
                 "ext-iconv": "To handle non UTF-8 CSV files (if \"php-intl\" is not already installed or is too limited)",
@@ -88,7 +90,7 @@
             "type": "library",
             "extra": {
                 "branch-alias": {
-                    "dev-master": "2.8.x-dev"
+                    "dev-master": "3.1.x-dev"
                 }
             },
             "autoload": {
@@ -125,7 +127,11 @@
                 "write",
                 "xlsx"
             ],
-            "time": "2017-09-25T19:44:35+00:00"
+            "support": {
+                "issues": "https://github.com/box/spout/issues",
+                "source": "https://github.com/box/spout/tree/v3.3.0"
+            },
+            "time": "2021-05-14T21:18:09+00:00"
         },
         {
             "name": "doctrine/instantiator",
@@ -1953,5 +1959,6 @@
     "platform": [],
     "platform-dev": {
         "ext-pdo": "*"
-    }
+    },
+    "plugin-api-version": "2.2.0"
 }