diff --git a/src/db/db/dbBoxScanner.h b/src/db/db/dbBoxScanner.h
index fe7cbbff0..6a59239dc 100644
--- a/src/db/db/dbBoxScanner.h
+++ b/src/db/db/dbBoxScanner.h
@@ -297,10 +297,10 @@ public:
    *  @brief Get the interactions between the stored objects
    *
    *  Two objects interact if the boxes of the objects enlarged by the given value overlap.
-   *  The enlargement is specified in units of width and height, i.e. half of the enlargement
-   *  is applied to one side before the overlap check.
    *
-   *  An enlargement of 1 means that boxes have to touch only in order to get an interaction.
+   *  An enlargement of 1 means that boxes have to touch in order to get an interaction.
+   *  An enlargement of 0 means that boxes have to overlap in order to get an interaction.
+   *  To capture interactions between object precisely spaced d, use d+1 for the enlargement.
    *
    *  The box scanner will report all interactions to the receiver object. See box_scanner_receiver
    *  for details about the methods that this object must provide. 
diff --git a/src/db/db/dbLocalOperation.h b/src/db/db/dbLocalOperation.h
index 8f8651865..28ef522c9 100644
--- a/src/db/db/dbLocalOperation.h
+++ b/src/db/db/dbLocalOperation.h
@@ -114,7 +114,8 @@ public:
 
   /**
    *  @brief Gets the interaction distance
-   *  A distance of means the shapes must overlap in order to interact.
+   *  A distance of zero means the shapes must overlap in order to interact.
+   *  A distance of 1 means the shapes need to touch in order to interact.
    */
   virtual db::Coord dist () const { return 0; }
 
diff --git a/src/db/db/dbRegionLocalOperations.cc b/src/db/db/dbRegionLocalOperations.cc
index 82c17c80e..1a2df425c 100644
--- a/src/db/db/dbRegionLocalOperations.cc
+++ b/src/db/db/dbRegionLocalOperations.cc
@@ -888,10 +888,10 @@ std::map<unsigned int, db::Coord>
 check_local_operation<TS, TI>::override_distance () const
 {
   //  makes sure, the "foreign"-type pseudo-intruder used for merging only
-  //  does not use the full search range, but only "touching".
+  //  does not use the full search range, but only "touching" (distance 1).
   std::map<unsigned int, db::Coord> od;
   if (check_local_operation_base<TS, TI>::m_has_other) {
-    od.insert (std::make_pair (1, 0));
+    od.insert (std::make_pair (1, 1));
   }
   return od;
 }
diff --git a/src/drc/unit_tests/drcSimpleTests.cc b/src/drc/unit_tests/drcSimpleTests.cc
index a4a2b489f..69a5c1d8b 100644
--- a/src/drc/unit_tests/drcSimpleTests.cc
+++ b/src/drc/unit_tests/drcSimpleTests.cc
@@ -2154,3 +2154,14 @@ TEST(152d_sep_with_props)
 {
   run_test (_this, "152", true);
 }
+
+// issue #2423
+TEST(153_issue_2423)
+{
+  run_test (_this, "153", false);
+}
+
+TEST(153d_issue_2423)
+{
+  run_test (_this, "153", true);
+}
diff --git a/testdata/drc/drcSimpleTests_151.drc b/testdata/drc/drcSimpleTests_151.drc
index 154464951..52f90704c 100644
--- a/testdata/drc/drcSimpleTests_151.drc
+++ b/testdata/drc/drcSimpleTests_151.drc
@@ -5,8 +5,6 @@ if $drc_test_deep
   deep
 end
 
-deep
-
 l1 = input(1, 0, enable_props)
 l1.output(1, 0)
 
diff --git a/testdata/drc/drcSimpleTests_153.drc b/testdata/drc/drcSimpleTests_153.drc
new file mode 100644
index 000000000..0f144bdaf
--- /dev/null
+++ b/testdata/drc/drcSimpleTests_153.drc
@@ -0,0 +1,16 @@
+
+source $drc_test_source
+target $drc_test_target
+
+if $drc_test_deep
+  deep
+end
+
+l1 = polygons(1, 0)
+l2 = polygons(2, 0)
+
+l1.output(1, 0)
+l2.output(2, 0)
+
+l1.separation(l2, 10.um).output(100, 0)
+
diff --git a/testdata/drc/drcSimpleTests_153.gds b/testdata/drc/drcSimpleTests_153.gds
new file mode 100644
index 000000000..de8c2013c
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diff --git a/testdata/drc/drcSimpleTests_au151.gds b/testdata/drc/drcSimpleTests_au151.gds
index 75622fd4b..9b4140845 100644
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diff --git a/testdata/drc/drcSimpleTests_au153.gds b/testdata/drc/drcSimpleTests_au153.gds
new file mode 100644
index 000000000..93a755d30
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diff --git a/testdata/drc/drcSimpleTests_au153d.gds b/testdata/drc/drcSimpleTests_au153d.gds
new file mode 100644
index 000000000..4a90a26c1
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