diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc
index ce99c205e7..6e9921ede7 100644
--- a/src/libstore/remote-store.cc
+++ b/src/libstore/remote-store.cc
@@ -332,7 +332,7 @@ PathSet RemoteStore::queryDerivationOutputNames(const Path & path)
     writeInt(wopQueryDerivationOutputNames, to);
     writeString(path, to);
     processStderr();
-    return readStringSet(from);
+    return readStrings<PathSet>(from);
 }
 
 
diff --git a/src/nix-worker/nix-worker.cc b/src/nix-worker/nix-worker.cc
index 68567f341e..f28905a24b 100644
--- a/src/nix-worker/nix-worker.cc
+++ b/src/nix-worker/nix-worker.cc
@@ -337,7 +337,7 @@ static void performOp(unsigned int clientVersion,
         StringSet names;
         names = store->queryDerivationOutputNames(path);
         stopWork();
-        writeStringSet(names, to);
+        writeStrings(names, to);
         break;
     }