diff --git a/app/forms/forum.py b/app/forms/forum.py
index ebaf849..c9ab038 100644
--- a/app/forms/forum.py
+++ b/app/forms/forum.py
@@ -8,7 +8,7 @@ class CommentForm(FlaskForm):
     message = TextAreaField('Message', validators=[DataRequired()])
     attachments = MultipleFileField('Pièces-jointes',
         validators=[vd.file.optional, vd.file.count, vd.file.extension,
-            vd.file.size])
+            vd.file.size, vd.file.namelength])
     submit = SubmitField('Commenter')
     preview = SubmitField('Prévisualiser')
 
diff --git a/app/utils/validators/file.py b/app/utils/validators/file.py
index 747ca0e..fd1f743 100644
--- a/app/utils/validators/file.py
+++ b/app/utils/validators/file.py
@@ -49,3 +49,13 @@ def size(form, files):
     else:
         if size > 500e3: # 500 ko per comment for a guest
             raise ValidationError("Fichiers trop lourds (max 500 ko)")
+
+def namelength(form, files):
+    errors = []
+    for f in files.data:
+        name = secure_filename(f.filename)
+        if len(name) > 64:
+            errors.append(f.filename)
+    if len(errors) > 0:
+        raise ValidationError(f"Noms trop longs, 64 caractères max " \
+            f"({', '.join(errors)})")