diff --git a/test/dijkstra_test.cc b/test/dijkstra_test.cc
--- a/test/dijkstra_test.cc
+++ b/test/dijkstra_test.cc
@@ -142,7 +142,7 @@
   LengthMap length(G);
 
   std::istringstream input(test_lgf);
-  digraphReader(input, G).
+  digraphReader(G, input).
     arcMap("length", length).
     node("source", s).
     node("target", t).