diff --git a/src/libstore/daemon.cc b/src/libstore/daemon.cc
index e5cfe94cb..2224d54d5 100644
--- a/src/libstore/daemon.cc
+++ b/src/libstore/daemon.cc
@@ -215,6 +215,8 @@ struct ClientSettings
                 for (auto & s : ss)
                     if (trusted.count(s))
                         subs.push_back(s);
+                    else if (!hasSuffix(s, "/") && trusted.count(s + "/"))
+                        subs.push_back(s + "/");
                     else
                         warn("ignoring untrusted substituter '%s'", s);
                 res = subs;