diff --git a/src/Plugin/CKEditorPlugin/DrupalUploadImage.php b/src/Plugin/CKEditorPlugin/DrupalUploadImage.php
index 7cb02a9..d3c7396 100644
--- a/src/Plugin/CKEditorPlugin/DrupalUploadImage.php
+++ b/src/Plugin/CKEditorPlugin/DrupalUploadImage.php
@@ -89,7 +89,7 @@ class DrupalUploadImage extends PluginBase implements CKEditorPluginInterface, C
     $filterFormatId = $editor->getFilterFormat()->id();
     $editorObj = editor_load($filterFormatId);
     $imageUploadSettings = $editorObj->getImageUploadSettings();
-    $maxFilesize = min(Bytes::toNumber($imageUploadSettings['max_size']), Environment::getUploadMaxSize());
+    $maxFilesize = min(Bytes::toNumber($imageUploadSettings['max_size'] ?? Environment::getUploadMaxSize()), Environment::getUploadMaxSize());
     return [
       'maxImageFilesize' => $maxFilesize,
       'imageUploadUrl' => Url::fromRoute('ckeditor_uploadimage.save', ['filterFormatId' => $filterFormatId])->toString(),
diff --git a/src/Plugin/CKEditorPlugin/DrupalUploadImageImce.php b/src/Plugin/CKEditorPlugin/DrupalUploadImageImce.php
index 023de15..203a6d2 100644
--- a/src/Plugin/CKEditorPlugin/DrupalUploadImageImce.php
+++ b/src/Plugin/CKEditorPlugin/DrupalUploadImageImce.php
@@ -89,7 +89,7 @@ class DrupalUploadImageImce extends PluginBase implements CKEditorPluginInterfac
     $filterFormatId = $editor->getFilterFormat()->id();
     $editorObj = editor_load($filterFormatId);
     $imageUploadSettings = $editorObj->getImageUploadSettings();
-    $maxFilesize = min(Bytes::toNumber($imageUploadSettings['max_size']), Environment::getUploadMaxSize());
+    $maxFilesize = min(Bytes::toNumber($imageUploadSettings['max_size'] ?? Environment::getUploadMaxSize()), Environment::getUploadMaxSize());
     return [
       'maxImageFilesize' => $maxFilesize,
       'imageUploadUrl' => Url::fromRoute('ckeditor_uploadimage.save', ['filterFormatId' => $filterFormatId])->toString(),