diff --git a/src/calibre/ebooks/docx/writer/tables.py b/src/calibre/ebooks/docx/writer/tables.py
index e821adc3c9..21bef908fc 100644
--- a/src/calibre/ebooks/docx/writer/tables.py
+++ b/src/calibre/ebooks/docx/writer/tables.py
@@ -142,8 +142,12 @@ class Cell(object):
             makeelement(tcPr, 'w:vMerge', w_val='restart')
         if self.col_span > 1:
             makeelement(tcPr, 'w:hMerge', w_val='restart')
+
         for item in self.items:
             item.serialize(tc)
+        if isinstance(item, Table):
+            # Word 2007 requires the last element in a table cell to be a paragraph
+            makeelement(tc, 'w:p')
 
     def applicable_borders(self, edge):
         if edge == 'left':