diff --git a/src/db/db/dbEdgeBoolean.h b/src/db/db/dbEdgeBoolean.h
index db495a873..449d3f8f1 100644
--- a/src/db/db/dbEdgeBoolean.h
+++ b/src/db/db/dbEdgeBoolean.h
@@ -24,6 +24,7 @@
 #define HDR_dbEdgeBoolean
 
 #include "dbEdge.h"
+#include "dbHash.h"
 #include "dbBoxScanner.h"
 
 #include "tlIntervalMap.h"
@@ -251,7 +252,7 @@ struct EdgeBooleanClusterCollector
     } else if (mp_intersections && p1 != p2) {
 
       std::pair<bool, db::Point> ip = o1->intersect_point (*o2);
-      if (ip.first) {
+      if (ip.first && m_seen_intersections.insert (ip.second).second) {
         mp_intersections->insert (db::Edge (ip.second, ip.second));
       }
 
@@ -260,6 +261,7 @@ struct EdgeBooleanClusterCollector
 
 private:
   OutputContainer *mp_intersections;
+  std::unordered_set<db::Point> m_seen_intersections;
 };
 
 }
diff --git a/src/db/unit_tests/dbEdges.cc b/src/db/unit_tests/dbEdges.cc
index 86d00817e..ace673825 100644
--- a/src/db/unit_tests/dbEdges.cc
+++ b/src/db/unit_tests/dbEdges.cc
@@ -852,6 +852,9 @@ TEST(22)
   ee.insert (db::Edge (4000,-2000,-2000,-2000));
 
   EXPECT_EQ ((e & ee).to_string (), "(400,0;-2000,0);(500,-174;400,0);(1000,0;900,-173);(4000,0;1000,0)");
+  EXPECT_EQ (e.intersections (ee).to_string (), "(400,0;400,0);(-2000,0;-2000,0);(1000,0;1000,0);(4000,0;4000,0);(400,0;-2000,0);(500,-174;400,0);(1000,0;900,-173);(4000,0;1000,0)");
+  //  no particular new points with intersections - just endpoints of original edges
+  EXPECT_EQ (e.intersections (ee).merged ().to_string (), "(400,0;-2000,0);(500,-174;400,0);(1000,0;900,-173);(4000,0;1000,0)");
 }
 
 TEST(23)