diff --git a/render/container.go b/render/container.go
index 2256b0582..82f054f28 100644
--- a/render/container.go
+++ b/render/container.go
@@ -82,12 +82,16 @@ func (c connectionJoin) Render(rpt report.Report) Nodes {
 			if !found {
 				id, found = ipNodes[report.MakeScopedEndpointNodeID(scope, addr, port)]
 			}
-			if found && id != "" { // not one we blanked out earlier
-				// We are guaranteed to find the id, so really this
-				// should never end up creating a node.
-				return id
+			if !found || id == "" {
+				return ""
 			}
-			return ""
+			// Not an IP we blanked out earlier.
+			//
+			// MapEndpoints is guaranteed to find a node with this id
+			// (and hence not have to create one), since we got the id
+			// from ipNodes, which is populated from c.topology, which
+			// is where MapEndpoints will look.
+			return id
 		}, c.topology).Render(rpt)
 }