diff --git a/changelog.d/10922.bugfix b/changelog.d/10922.bugfix
new file mode 100644
index 0000000000..b7315514e0
--- /dev/null
+++ b/changelog.d/10922.bugfix
@@ -0,0 +1 @@
+Fix a minor bug in the response to `/_matrix/client/r0/voip/turnServer`. Contributed by @lukaslihotzki.
diff --git a/synapse/rest/client/voip.py b/synapse/rest/client/voip.py
index ea2b8aa45f..ea7e025156 100644
--- a/synapse/rest/client/voip.py
+++ b/synapse/rest/client/voip.py
@@ -70,7 +70,7 @@ class VoipRestServlet(RestServlet):
             {
                 "username": username,
                 "password": password,
-                "ttl": userLifetime / 1000,
+                "ttl": userLifetime // 1000,
                 "uris": turnUris,
             },
         )