diff --git a/pyoo.py b/pyoo.py
index 23e3e6b..1b53dd3 100644
--- a/pyoo.py
+++ b/pyoo.py
@@ -1829,7 +1829,7 @@ def create_spreadsheet(self):
         document = self._open_url(url)
         return SpreadsheetDocument(document)
 
-    def open_spreadsheet(self, path, as_template=False):
+    def open_spreadsheet(self, path, as_template=False, read_only=False):
         """
         Opens an exiting spreadsheet document on the local file system.
         """
@@ -1839,6 +1839,11 @@ def open_spreadsheet(self, path, as_template=False):
             pv.Name = 'AsTemplate'
             pv.Value = True
             extra += (pv,)
+        if read_only:
+            pv = uno.createUnoStruct('com.sun.star.beans.PropertyValue')
+            pv.Name = 'ReadOnly'
+            pv.Value = True
+            extra += (pv,)
         # UNO requires absolute paths
         url = uno.systemPathToFileUrl(os.path.abspath(path))
         document = self._open_url(url, extra)