diff --git a/include/contractor/graph_contractor.hpp b/include/contractor/graph_contractor.hpp
index 08015bede..b61d3d775 100644
--- a/include/contractor/graph_contractor.hpp
+++ b/include/contractor/graph_contractor.hpp
@@ -402,7 +402,7 @@ class GraphContractor
 
         unsigned current_level = 0;
         bool flushed_contractor = false;
-        while (number_of_nodes > 2 &&
+        while (remaining_nodes.size() > 1 &&
                number_of_contracted_nodes < static_cast<NodeID>(number_of_nodes * core_factor))
         {
             if (!flushed_contractor && (number_of_contracted_nodes >
@@ -513,16 +513,20 @@ class GraphContractor
                 {
                     const EdgeID current_edge_ID =
                         contractor_graph->FindEdge(edge.source, edge.target);
-                    if (current_edge_ID < contractor_graph->EndEdges(edge.source))
+                    if (current_edge_ID != SPECIAL_EDGEID)
                     {
                         ContractorGraph::EdgeData &current_data =
                             contractor_graph->GetEdgeData(current_edge_ID);
                         if (current_data.shortcut && edge.data.forward == current_data.forward &&
-                            edge.data.backward == current_data.backward &&
-                            edge.data.weight < current_data.weight)
+                            edge.data.backward == current_data.backward)
                         {
-                            // found a duplicate edge with smaller weight, update it.
-                            current_data = edge.data;
+                            // we found a duplicate edge
+                            // if weight of new one is smaller, update old one
+                            if (edge.data.weight < current_data.weight)
+                            {
+                                current_data = edge.data;
+                            }
+                            // don't insert duplicates
                             continue;
                         }
                     }
@@ -559,7 +563,7 @@ class GraphContractor
 
         if (remaining_nodes.size() > 2)
         {
-            if (orig_node_id_from_new_node_id_map.size() > 0)
+            if (flushed_contractor)
             {
                 tbb::parallel_for(
                     tbb::blocked_range<NodeID>(0, remaining_nodes.size(), InitGrainSize),
@@ -727,7 +731,7 @@ class GraphContractor
             if (heap.GetData(node).target)
             {
                 ++number_of_targets_found;
-                if (number_of_targets_found >= number_of_targets)
+                if (number_of_targets_found == number_of_targets)
                 {
                     return;
                 }
@@ -808,7 +812,9 @@ class GraphContractor
                 }
                 const NodeID target = contractor_graph->GetTarget(out_edge);
                 if (node == target)
+                {
                     continue;
+                }
 
                 const EdgeWeight path_weight = in_data.weight + out_data.weight;
                 if (target == source)