diff --git a/test/kruskal_test.cc b/test/kruskal_test.cc
new file mode 100644
--- /dev/null
+++ b/test/kruskal_test.cc
@@ -0,0 +1,149 @@
+/* -*- C++ -*-
+ *
+ * This file is a part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2003-2008
+ * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+#include <iostream>
+#include <vector>
+
+#include "test_tools.h"
+#include <lemon/maps.h>
+#include <lemon/kruskal.h>
+#include <lemon/list_graph.h>
+
+#include <lemon/concepts/maps.h>
+#include <lemon/concepts/digraph.h>
+#include <lemon/concepts/graph.h>
+
+
+using namespace std;
+using namespace lemon;
+
+void checkCompileKruskal()
+{
+  concepts::WriteMap<concepts::Digraph::Arc,bool> w;
+  concepts::WriteMap<concepts::Graph::Edge,bool> uw;
+
+  concepts::ReadMap<concepts::Digraph::Arc,int> r;
+  concepts::ReadMap<concepts::Graph::Edge,int> ur;
+
+  concepts::Digraph g;
+  concepts::Graph ug;
+
+  kruskal(g, r, w);
+  kruskal(ug, ur, uw);
+
+  std::vector<std::pair<concepts::Digraph::Arc, int> > rs;
+  std::vector<std::pair<concepts::Graph::Edge, int> > urs;
+
+  kruskal(g, rs, w);
+  kruskal(ug, urs, uw);
+
+  std::vector<concepts::Digraph::Arc> ws;
+  std::vector<concepts::Graph::Edge> uws;
+
+  kruskal(g, r, ws.begin());
+  kruskal(ug, ur, uws.begin());
+
+}
+
+int main() {
+
+  typedef ListGraph::Node Node;
+  typedef ListGraph::Edge Edge;
+  typedef ListGraph::NodeIt NodeIt;
+  typedef ListGraph::ArcIt ArcIt;
+
+  ListGraph G;
+
+  Node s=G.addNode();
+  Node v1=G.addNode();
+  Node v2=G.addNode();
+  Node v3=G.addNode();
+  Node v4=G.addNode();
+  Node t=G.addNode();
+  
+  Edge e1 = G.addEdge(s, v1);
+  Edge e2 = G.addEdge(s, v2);
+  Edge e3 = G.addEdge(v1, v2);
+  Edge e4 = G.addEdge(v2, v1);
+  Edge e5 = G.addEdge(v1, v3);
+  Edge e6 = G.addEdge(v3, v2);
+  Edge e7 = G.addEdge(v2, v4);
+  Edge e8 = G.addEdge(v4, v3);
+  Edge e9 = G.addEdge(v3, t);
+  Edge e10 = G.addEdge(v4, t);
+
+  typedef ListGraph::EdgeMap<int> ECostMap;
+  typedef ListGraph::EdgeMap<bool> EBoolMap;
+
+  ECostMap edge_cost_map(G, 2);
+  EBoolMap tree_map(G);
+  
+
+  //Test with const map.
+  check(kruskal(G, ConstMap<ListGraph::Edge,int>(2), tree_map)==10,
+	"Total cost should be 10");
+  //Test with a edge map (filled with uniform costs).
+  check(kruskal(G, edge_cost_map, tree_map)==10,
+	"Total cost should be 10");
+
+  edge_cost_map.set(e1, -10);
+  edge_cost_map.set(e2, -9);
+  edge_cost_map.set(e3, -8);
+  edge_cost_map.set(e4, -7);
+  edge_cost_map.set(e5, -6);
+  edge_cost_map.set(e6, -5);
+  edge_cost_map.set(e7, -4);
+  edge_cost_map.set(e8, -3);
+  edge_cost_map.set(e9, -2);
+  edge_cost_map.set(e10, -1);
+
+  vector<Edge> tree_edge_vec(5);
+
+  //Test with a edge map and inserter.
+  check(kruskal(G, edge_cost_map,
+		 tree_edge_vec.begin())
+	==-31,
+	"Total cost should be -31.");
+  
+  tree_edge_vec.clear();
+
+  check(kruskal(G, edge_cost_map,
+		back_inserter(tree_edge_vec))
+	==-31,
+	"Total cost should be -31.");
+  
+//   tree_edge_vec.clear();
+  
+//   //The above test could also be coded like this:
+//   check(kruskal(G,
+// 		makeKruskalMapInput(G, edge_cost_map),
+// 		makeKruskalSequenceOutput(back_inserter(tree_edge_vec)))
+// 	==-31,
+// 	"Total cost should be -31.");
+
+  check(tree_edge_vec.size()==5,"The tree should have 5 edges.");
+
+  check(tree_edge_vec[0]==e1 &&
+	tree_edge_vec[1]==e2 &&
+	tree_edge_vec[2]==e5 &&
+	tree_edge_vec[3]==e7 &&
+	tree_edge_vec[4]==e9,
+	"Wrong tree.");
+
+  return 0;
+}