diff --git a/src/engine/joinOrdering/CostIKKBZ.h b/src/engine/joinOrdering/CostIKKBZ.h
index d9b2dba071..2053c54972 100644
--- a/src/engine/joinOrdering/CostIKKBZ.h
+++ b/src/engine/joinOrdering/CostIKKBZ.h
@@ -15,7 +15,7 @@ namespace JoinOrdering {
 template <typename N>
 requires RelationAble<N> class CostIKKBZ : public ICostASI<N> {
  public:
-  ad_utility::HashMap<N, float> rank_m;
+  //  ad_utility::HashMap<N, float> rank_m;
 
   auto rank(const QueryGraph<N>& g, const N& n) -> float;
 
diff --git a/src/engine/joinOrdering/GOO.cpp b/src/engine/joinOrdering/GOO.cpp
index 1dff9978c7..5f662d8f65 100644
--- a/src/engine/joinOrdering/GOO.cpp
+++ b/src/engine/joinOrdering/GOO.cpp
@@ -45,19 +45,7 @@ requires RelationAble<N>
   g.hist[n].push_back(b);
 
   // TODO: STL chain iterators
-  // boost::join(g.edges_[a], g.edges_[b])
-  for (auto const& [x, e] : g.edges_[a]) {
-    if (e.hidden || x == a || x == b) continue;
-    g.add_rjoin(n, x, e.weight, Direction::UNDIRECTED);
-
-    if (!g.is_common_neighbour(a, b, x)) continue;
-    // when the 2 relations to be combined have common neighbours
-    // multiply edge weights of newly combined relation
-    g.edges_[x][n].weight = g.edges_[a][x].weight * g.edges_[b][x].weight;
-    g.edges_[n][x].weight = g.edges_[a][x].weight * g.edges_[b][x].weight;
-  }
-
-  for (auto const& [x, e] : g.edges_[b]) {
+  for (auto const& [x, e] : boost::join(g.edges_[a], g.edges_[b])) {
     if (e.hidden || x == a || x == b) continue;
     g.add_rjoin(n, x, e.weight, Direction::UNDIRECTED);
 
diff --git a/src/engine/joinOrdering/GOO.h b/src/engine/joinOrdering/GOO.h
index 24678c8c4d..bb55cd1b38 100644
--- a/src/engine/joinOrdering/GOO.h
+++ b/src/engine/joinOrdering/GOO.h
@@ -6,6 +6,7 @@
 #pragma once
 
 #include "QueryGraph.h"
+#include "boost/range/join.hpp"
 
 namespace JoinOrdering {
 
diff --git a/src/engine/joinOrdering/IKKBZ.cpp b/src/engine/joinOrdering/IKKBZ.cpp
index 39037a72a7..1e05f6aa01 100644
--- a/src/engine/joinOrdering/IKKBZ.cpp
+++ b/src/engine/joinOrdering/IKKBZ.cpp
@@ -117,14 +117,16 @@ std::vector<N> IKKBZ_Normalized(QueryGraph<N>& g, ICostASI<N>& Ch,
           normalized = false;
         }
     }
-    if (normalized) return subtree;
+    //    if (normalized) return subtree;
+    if (normalized) return g.iter(subtree_root);
   }
 }
 
 template <typename N>
 requires RelationAble<N>
-void IKKBZ_merge(QueryGraph<N>& g, ICostASI<N>& Ch, std::vector<N>& dv) {
+void IKKBZ_merge(QueryGraph<N>& g, ICostASI<N>& Ch, std::vector<N>& xx) {
   // we get here after we are already sure that descendents are in a chain
+  auto dv = std::vector(xx.begin(), xx.end());
 
   // exclude n from sorting. subchain root not considered during sorting.
   // n is always at the beginning of dv
diff --git a/src/engine/joinOrdering/QueryGraph.cpp b/src/engine/joinOrdering/QueryGraph.cpp
index 20c59f4654..6917310c16 100644
--- a/src/engine/joinOrdering/QueryGraph.cpp
+++ b/src/engine/joinOrdering/QueryGraph.cpp
@@ -178,11 +178,10 @@ auto QueryGraph<N>::get_chained_subtree(const N& n) -> N {
 
   // since this is called from IKKBZ_Normalize
   // we have already checked the existence of a subtree
-  //  if (it != dxs.end())
-  return *it;
+  if (it != dxs.end()) return *it;
 
   //  AD_CONTRACT_CHECK(false);
-  //  throw std::runtime_error("how did we get here?");
+  throw std::runtime_error("how did we get here?");
 }
 
 template <typename N>
diff --git a/test/engine/joinOrdering/IKKBZTest.cpp b/test/engine/joinOrdering/IKKBZTest.cpp
index ca6b613d13..9161b13305 100644
--- a/test/engine/joinOrdering/IKKBZTest.cpp
+++ b/test/engine/joinOrdering/IKKBZTest.cpp
@@ -578,7 +578,6 @@ TEST(GOO_SANITY, SESSION04_EX) {
 
   // TODO: undeterministic
   //  EXPECT_NO_THROW(JoinOrdering::GOO(g));
-  JoinOrdering::GOO(g);
   //  auto erg = JoinOrdering::GOO(g);
   //  for (auto const& x : g.hist[erg]) std::cout << x.getLabel() << "\n";
 }