diff --git a/composer.json b/composer.json
index 8c2b642..938b9a1 100644
--- a/composer.json
+++ b/composer.json
@@ -4,7 +4,7 @@
   "type": "library",
   "license": "MIT",
   "require": {
-    "robmorgan/phinx": "^0.8.1||^0.9.0||^0.10.0"
+    "robmorgan/phinx": "^0.11"
   },
   "require-dev": {
     "phpunit/phpunit": "^5.7"
diff --git a/src/CsvSeeder.php b/src/CsvSeeder.php
index f94115b..2b47da6 100644
--- a/src/CsvSeeder.php
+++ b/src/CsvSeeder.php
@@ -110,6 +110,10 @@ private function buildToInsertArray($csvRows, $mapping)
         for ($i = $offset; $i < count($csvRows); $i++) {
             $temp = [];
             foreach ($mapping as $key => $value) {
+                // replace empty csv columns with null
+                if (empty($csvRows[$i][$key])) {
+                    $csvRows[$i][$key] = null;
+                }
                 $temp[$value] = $csvRows[$i][$key];
             }
             $toBuild[] = $temp;