diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py
index afaaeeacdd..c971a6d731 100644
--- a/synapse/rest/client/v2_alpha/account.py
+++ b/synapse/rest/client/v2_alpha/account.py
@@ -529,7 +529,7 @@ class ThreepidRestServlet(RestServlet):
 
 
 class ThreepidUnbindRestServlet(RestServlet):
-    PATTERNS = client_patterns("/account/3pid/unbind$")
+    PATTERNS = client_patterns("/account/3pid/unbind$", unstable=True)
 
     def __init__(self, hs):
         super(ThreepidUnbindRestServlet, self).__init__()