diff --git a/changelog.d/15180.bugfix b/changelog.d/15180.bugfix
new file mode 100644
index 000000000000..e7a3dcd41a37
--- /dev/null
+++ b/changelog.d/15180.bugfix
@@ -0,0 +1 @@
+Fix a bug introduced in Synapse 1.78.0 where requests to claim dehydrated devices would fail with a `405` error.
diff --git a/synapse/rest/client/devices.py b/synapse/rest/client/devices.py
index 486c6dbbc5b3..dab4a77f7e7c 100644
--- a/synapse/rest/client/devices.py
+++ b/synapse/rest/client/devices.py
@@ -255,7 +255,7 @@ class DehydratedDeviceServlet(RestServlet):
 
     """
 
-    PATTERNS = client_patterns("/org.matrix.msc2697.v2/dehydrated_device", releases=())
+    PATTERNS = client_patterns("/org.matrix.msc2697.v2/dehydrated_device$", releases=())
 
     def __init__(self, hs: "HomeServer"):
         super().__init__()