diff --git a/src/Services/Misc/FAIconGenerator.php b/src/Services/Misc/FAIconGenerator.php
index 997e9f39..18db1fad 100644
--- a/src/Services/Misc/FAIconGenerator.php
+++ b/src/Services/Misc/FAIconGenerator.php
@@ -56,9 +56,6 @@ class FAIconGenerator
      */
     public function fileExtensionToFAType(string $extension): string
     {
-        if ('' === $extension) {
-            throw new InvalidArgumentException('You must specify an extension!');
-        }
         //Normalize file extension
         $extension = strtolower($extension);
         foreach (self::EXT_MAPPING as $fa => $exts) {
diff --git a/src/Twig/AttachmentExtension.php b/src/Twig/AttachmentExtension.php
index fd93de9a..9f81abe6 100644
--- a/src/Twig/AttachmentExtension.php
+++ b/src/Twig/AttachmentExtension.php
@@ -39,8 +39,8 @@ final class AttachmentExtension extends AbstractExtension
         return [
             /* Returns the URL to a thumbnail of the given attachment */
             new TwigFunction('attachment_thumbnail', fn(Attachment $attachment, string $filter_name = 'thumbnail_sm'): ?string => $this->attachmentURLGenerator->getThumbnailURL($attachment, $filter_name)),
-            /* Returns the font awesome icon class which is representing the given file extension  */
-            new TwigFunction('ext_to_fa_icon', fn(string $extension): string => $this->FAIconGenerator->fileExtensionToFAType($extension)),
+            /* Returns the font awesome icon class which is representing the given file extension (We allow null here for attachments without extension) */
+            new TwigFunction('ext_to_fa_icon', fn(?string $extension): string => $this->FAIconGenerator->fileExtensionToFAType($extension ?? '')),
         ];
     }
 }