diff --git a/src/python/WMCore/Credential/Proxy.py b/src/python/WMCore/Credential/Proxy.py
index 0cd47d8cad..7c6e9313e8 100644
--- a/src/python/WMCore/Credential/Proxy.py
+++ b/src/python/WMCore/Credential/Proxy.py
@@ -159,6 +159,8 @@ def setEnv(self, cmd):
         if self.uisource is not None and len(self.uisource) > 0:
             ret = 'source ' + self.uisource + ' && ' + ret
         if self.cleanEnvironment:
+            # Need to escape ' in cmd
+            ret = ret.replace("'", r"'\''")
             ret = "env -i sh -c '%s'" % ret
 
         return ret
@@ -732,4 +734,4 @@ def getAllUserGroups(self, proxy):
         for attribute in attributes:
             splAttr = attribute.split('/') #splitted attribut
             filtAttr = [part for part in splAttr if not (part.startswith('Role=') or part.startswith('Capability='))] #filtered attribute
-            yield '/'.join(filtAttr)
\ No newline at end of file
+            yield '/'.join(filtAttr)