diff --git a/types/netmap/nodemut.go b/types/netmap/nodemut.go
index ab30ef1e6..f4de1bf0b 100644
--- a/types/netmap/nodemut.go
+++ b/types/netmap/nodemut.go
@@ -69,17 +69,6 @@ func (m NodeMutationLastSeen) Apply(n *tailcfg.Node) {
 	n.LastSeen = ptr.To(m.LastSeen)
 }
 
-// NodeMutationCap is a NodeMutation that says a node's
-// [tailcfg.CapabilityVersion] value has changed.
-type NodeMutationCap struct {
-	mutatingNodeID
-	Cap tailcfg.CapabilityVersion
-}
-
-func (m NodeMutationCap) Apply(n *tailcfg.Node) {
-	n.Cap = m.Cap
-}
-
 var peerChangeFields = sync.OnceValue(func() []reflect.StructField {
 	var fields []reflect.StructField
 	rt := reflect.TypeFor[tailcfg.PeerChange]()
@@ -116,8 +105,6 @@ func NodeMutationsFromPatch(p *tailcfg.PeerChange) (_ []NodeMutation, ok bool) {
 			ret = append(ret, NodeMutationOnline{mutatingNodeID(p.NodeID), *p.Online})
 		case "LastSeen":
 			ret = append(ret, NodeMutationLastSeen{mutatingNodeID(p.NodeID), *p.LastSeen})
-		case "Cap":
-			ret = append(ret, NodeMutationCap{mutatingNodeID(p.NodeID), p.Cap})
 		}
 	}
 	return ret, true
diff --git a/types/netmap/nodemut_test.go b/types/netmap/nodemut_test.go
index 0f1cac6b2..374f8623a 100644
--- a/types/netmap/nodemut_test.go
+++ b/types/netmap/nodemut_test.go
@@ -177,14 +177,6 @@ func TestMutationsFromMapResponse(t *testing.T) {
 			},
 			want: nil,
 		},
-		{
-			name: "patch-cap",
-			mr: fromChanges(&tailcfg.PeerChange{
-				NodeID: 1,
-				Cap:    2,
-			}),
-			want: muts(NodeMutationCap{1, 2}),
-		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -203,7 +195,6 @@ func TestMutationsFromMapResponse(t *testing.T) {
 					NodeMutationDERPHome{},
 					NodeMutationOnline{},
 					NodeMutationLastSeen{},
-					NodeMutationCap{},
 				)); diff != "" {
 				t.Errorf("wrong result (-want +got):\n%s", diff)
 			}
diff --git a/wgengine/magicsock/magicsock.go b/wgengine/magicsock/magicsock.go
index a6c6a3fb6..bfc7afba9 100644
--- a/wgengine/magicsock/magicsock.go
+++ b/wgengine/magicsock/magicsock.go
@@ -3263,10 +3263,6 @@ func (c *Conn) onNodeMutationsUpdate(update NodeMutationsUpdate) {
 			ep.mu.Lock()
 			ep.setEndpointsLocked(views.SliceOf(m.Endpoints))
 			ep.mu.Unlock()
-		case netmap.NodeMutationCap:
-			ep.mu.Lock()
-			ep.relayCapable = capVerIsRelayCapable(m.Cap)
-			ep.mu.Unlock()
 		}
 	}
 }