diff --git a/src/python/WMCore/Services/Rucio/Rucio.py b/src/python/WMCore/Services/Rucio/Rucio.py
index db4f239821..69ec944fe4 100644
--- a/src/python/WMCore/Services/Rucio/Rucio.py
+++ b/src/python/WMCore/Services/Rucio/Rucio.py
@@ -302,7 +302,7 @@ def getPFN(self, site, lfns, protocol=None, protocolDomain='ALL', operation=None
         :param protocol: If the RSE supports multiple access protocols, a preferred protocol can be selected via this,
                          otherwise the default one for the site will be selected. Example: 'gsiftp' or 'davs'
                          this is what is called "scheme" in the RUCIO API (we think protocol is more clear)
-        :param protocolDomain: The scope of the protocol. Supported are ‘LAN’, ‘WAN’, and ‘ALL’ (as default)
+        :param protocolDomain: The scope of the protocol. Supported are "LAN", "WAN", and "ALL" (as default)
                                 this is what is called protocol_domain in RUCIO API, changed for CMS camelCase convention
         :param operation: The name of the requested operation (read, write, or delete). If None, all operations are queried
         :return: a dictionary having the LFN's as keys and the corresponding PFN's as values.