diff --git a/xpra/client/mixins/mmap.py b/xpra/client/mixins/mmap.py
index d7f7abd6a7..410e9413a0 100644
--- a/xpra/client/mixins/mmap.py
+++ b/xpra/client/mixins/mmap.py
@@ -4,6 +4,7 @@
 # later version. See the file COPYING for details.
 
 import os
+from random import randint
 
 from xpra.util import envbool, typedict
 from xpra.os_util import get_int_uuid
@@ -132,7 +133,7 @@ def init_mmap(self, mmap_filename, mmap_group, socket_filename):
         if self.mmap_enabled:
             self.mmap_token = get_int_uuid()
             self.mmap_token_bytes = DEFAULT_TOKEN_BYTES
-            self.mmap_token_index = self.mmap_size - DEFAULT_TOKEN_BYTES
+            self.mmap_token_index = randint(0, self.mmap_size - DEFAULT_TOKEN_BYTES)
             write_mmap_token(self.mmap, self.mmap_token, self.mmap_token_index, self.mmap_token_bytes)
 
     def clean_mmap(self):
diff --git a/xpra/server/source/mmap_connection.py b/xpra/server/source/mmap_connection.py
index 2a5c4ce004..f61e3c9bbf 100644
--- a/xpra/server/source/mmap_connection.py
+++ b/xpra/server/source/mmap_connection.py
@@ -4,6 +4,8 @@
 # Xpra is released under the terms of the GNU GPL v2, or, at your option, any
 # later version. See the file COPYING for details.
 
+from random import randint
+
 from xpra.util import typedict
 from xpra.server.source.stub_source_mixin import StubSourceMixin
 
@@ -109,7 +111,7 @@ def mmapattr(k):
                     from xpra.os_util import get_int_uuid
                     self.mmap_client_token = get_int_uuid()
                     self.mmap_client_token_bytes = DEFAULT_TOKEN_BYTES
-                    self.mmap_client_token_index = self.mmap_size-self.mmap_client_token_bytes
+                    self.mmap_client_token_index = randint(0, self.mmap_size-self.mmap_client_token_bytes)
                     write_mmap_token(self.mmap,
                                      self.mmap_client_token,
                                      self.mmap_client_token_index,