diff --git a/odoo/tools/misc.py b/odoo/tools/misc.py
index 19470b07b0079..ca20ab3278b23 100644
--- a/odoo/tools/misc.py
+++ b/odoo/tools/misc.py
@@ -372,11 +372,12 @@ class PatchedXlsxWorkbook(xlsxwriter.Workbook):
 
         # TODO when xlsxwriter bump to 0.9.8, add worksheet_class=None parameter instead of kw
         def add_worksheet(self, name=None, **kw):
-            # invalid Excel character: []:*?/\
-            name = re.sub(r'[\[\]:*?/\\]', '', name)
+            if name:
+                # invalid Excel character: []:*?/\
+                name = re.sub(r'[\[\]:*?/\\]', '', name)
 
-            # maximum size is 31 characters
-            name = name[:31]
+                # maximum size is 31 characters
+                name = name[:31]
             return super(PatchedXlsxWorkbook, self).add_worksheet(name, **kw)
 
     xlsxwriter.Workbook = PatchedXlsxWorkbook