diff --git a/addons/web/controllers/main.py b/addons/web/controllers/main.py
index 1d3d1327a79..5d22d1f4224 100644
--- a/addons/web/controllers/main.py
+++ b/addons/web/controllers/main.py
@@ -720,7 +720,7 @@ class ExportXlsxWriter:
         # Write main header
         for i, fieldname in enumerate(self.field_names):
             self.write(0, i, fieldname, self.header_style)
-        self.worksheet.set_column(0, i, 30) # around 220 pixels
+        self.worksheet.set_column(0, max(0, len(self.field_names) - 1), 30) # around 220 pixels
 
     def close(self):
         self.workbook.close()