diff --git a/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.cc b/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.cc
index 06a1c4df5..63d4b2685 100644
--- a/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.cc
+++ b/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.cc
@@ -349,7 +349,8 @@ LEFDEFReaderOptions::LEFDEFReaderOptions ()
     m_special_routing_datatype (0),
     m_separate_groups (false),
     m_map_file (),
-    m_macro_resolution_mode (0)
+    m_macro_resolution_mode (false),
+    m_read_lef_with_def (true)
 {
   //  .. nothing yet ..
 }
@@ -418,6 +419,7 @@ LEFDEFReaderOptions &LEFDEFReaderOptions::operator= (const LEFDEFReaderOptions &
     m_map_file = d.m_map_file;
     m_macro_resolution_mode = d.m_macro_resolution_mode;
     m_lef_files = d.m_lef_files;
+    m_read_lef_with_def = d.m_read_lef_with_def;
   }
   return *this;
 }
diff --git a/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.h b/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.h
index efa621b15..4009a7ad6 100644
--- a/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.h
+++ b/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.h
@@ -738,6 +738,16 @@ public:
     m_lef_files = lf;
   }
 
+  bool read_lef_with_def () const
+  {
+    return m_read_lef_with_def;
+  }
+
+  void set_read_lef_with_def (bool f)
+  {
+    m_read_lef_with_def = f;
+  }
+
   bool separate_groups () const
   {
     return m_separate_groups;
@@ -829,6 +839,7 @@ private:
   bool m_separate_groups;
   std::string m_map_file;
   unsigned int m_macro_resolution_mode;
+  bool m_read_lef_with_def;
   std::vector<std::string> m_lef_files;
 };
 
diff --git a/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFPlugin.cc b/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFPlugin.cc
index 468bc40e4..6ac19b03f 100644
--- a/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFPlugin.cc
+++ b/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFPlugin.cc
@@ -158,22 +158,26 @@ private:
 
       //  Additionally read all LEF files next to the DEF file
 
-      std::string input_dir = tl::absolute_path (m_stream.absolute_path ());
+      if (lefdef_options->read_lef_with_def ()) {
 
-      if (tl::file_exists (input_dir)) {
+        std::string input_dir = tl::absolute_path (m_stream.absolute_path ());
 
-        std::vector<std::string> entries = tl::dir_entries (input_dir);
-        for (std::vector<std::string>::const_iterator e = entries.begin (); e != entries.end (); ++e) {
+        if (tl::file_exists (input_dir)) {
 
-          if (is_lef_format (*e)) {
+          std::vector<std::string> entries = tl::dir_entries (input_dir);
+          for (std::vector<std::string>::const_iterator e = entries.begin (); e != entries.end (); ++e) {
 
-            std::string lp = tl::combine_path (input_dir, *e);
+            if (is_lef_format (*e)) {
 
-            tl::SelfTimer timer (tl::verbosity () >= 21, tl::to_string (tr ("Reading LEF file: ")) + lp);
+              std::string lp = tl::combine_path (input_dir, *e);
 
-            tl::InputStream lef_stream (lp);
-            tl::log << tl::to_string (tr ("Reading")) << " " << lp;
-            importer.read_lef (lef_stream, layout, state);
+              tl::SelfTimer timer (tl::verbosity () >= 21, tl::to_string (tr ("Reading LEF file: ")) + lp);
+
+              tl::InputStream lef_stream (lp);
+              tl::log << tl::to_string (tr ("Reading")) << " " << lp;
+              importer.read_lef (lef_stream, layout, state);
+
+            }
 
           }
 
@@ -323,6 +327,7 @@ class LEFDEFFormatDeclaration
       tl::make_member (&LEFDEFReaderOptions::special_routing_datatype_str, &LEFDEFReaderOptions::set_special_routing_datatype_str, "special-routing-datatype-string") +
       tl::make_member (&LEFDEFReaderOptions::via_cellname_prefix, &LEFDEFReaderOptions::set_via_cellname_prefix, "via-cellname-prefix") +
       tl::make_member (&LEFDEFReaderOptions::begin_lef_files, &LEFDEFReaderOptions::end_lef_files, &LEFDEFReaderOptions::push_lef_file, "lef-files") +
+      tl::make_member (&LEFDEFReaderOptions::read_lef_with_def, &LEFDEFReaderOptions::set_read_lef_with_def, "read-lef-with-def") +
       tl::make_member (&LEFDEFReaderOptions::macro_resolution_mode, &LEFDEFReaderOptions::set_macro_resolution_mode, "macro-resolution-mode", MacroResolutionModeConverter ()) +
       tl::make_member (&LEFDEFReaderOptions::separate_groups, &LEFDEFReaderOptions::set_separate_groups, "separate-groups") +
       tl::make_member (&LEFDEFReaderOptions::map_file, &LEFDEFReaderOptions::set_map_file, "map-file")
diff --git a/src/plugins/streamers/lefdef/db_plugin/gsiDeclDbLEFDEF.cc b/src/plugins/streamers/lefdef/db_plugin/gsiDeclDbLEFDEF.cc
index fe963515c..c8bcf3ea6 100644
--- a/src/plugins/streamers/lefdef/db_plugin/gsiDeclDbLEFDEF.cc
+++ b/src/plugins/streamers/lefdef/db_plugin/gsiDeclDbLEFDEF.cc
@@ -712,6 +712,20 @@ gsi::Class<db::LEFDEFReaderOptions> decl_lefdef_config ("db", "LEFDEFReaderConfi
   gsi::method ("lef_files=", &db::LEFDEFReaderOptions::set_lef_files,
     "@brief Sets the list technology LEF files to additionally import\n"
     "See \\lef_files for details."
+  ) +
+  gsi::method ("read_lef_with_def", &db::LEFDEFReaderOptions::read_lef_with_def,
+    "@brief Gets a value indicating whether to read all LEF files in the same directory than the DEF file.\n"
+    "If this property is set to true (the default), the DEF reader will automatically consume all LEF files "
+    "next to the DEF file in addition to the LEF files specified with \\lef_files. If set to false, only the "
+    "LEF files specified with \\lef_files will be read.\n"
+    "\n"
+    "This property has been added in version 0.27.\n"
+  ) +
+  gsi::method ("read_lef_with_def=", &db::LEFDEFReaderOptions::set_read_lef_with_def, gsi::arg ("flag"),
+    "@brief Sets a value indicating whether to read all LEF files in the same directory than the DEF file.\n"
+    "See \\read_lef_with_def for details about this property.\n"
+    "\n"
+    "This property has been added in version 0.27.\n"
   ),
   "@brief Detailed LEF/DEF reader options\n"
   "This class is a aggregate belonging to the \\LoadLayoutOptions class. It provides options for the LEF/DEF reader. "
diff --git a/src/plugins/streamers/lefdef/lay_plugin/LEFDEFTechnologyComponentEditor.ui b/src/plugins/streamers/lefdef/lay_plugin/LEFDEFTechnologyComponentEditor.ui
index bd6cf1950..9f3ed99f4 100644
--- a/src/plugins/streamers/lefdef/lay_plugin/LEFDEFTechnologyComponentEditor.ui
+++ b/src/plugins/streamers/lefdef/lay_plugin/LEFDEFTechnologyComponentEditor.ui
@@ -41,7 +41,7 @@
       </size>
      </property>
      <property name="title">
-      <string>LEF Files (specify what LEF files to use additionally)</string>
+      <string>LEF Files</string>
      </property>
      <property name="flat">
       <bool>true</bool>
@@ -189,6 +189,13 @@
         </layout>
        </widget>
       </item>
+      <item>
+       <widget class="QCheckBox" name="read_lef_with_def">
+        <property name="text">
+         <string>for DEF: also read all LEF files in the same directory than the DEF file</string>
+        </property>
+       </widget>
+      </item>
      </layout>
     </widget>
    </item>
diff --git a/src/plugins/streamers/lefdef/lay_plugin/layLEFDEFImportDialogs.cc b/src/plugins/streamers/lefdef/lay_plugin/layLEFDEFImportDialogs.cc
index 94697f9c4..7693f38c7 100644
--- a/src/plugins/streamers/lefdef/lay_plugin/layLEFDEFImportDialogs.cc
+++ b/src/plugins/streamers/lefdef/lay_plugin/layLEFDEFImportDialogs.cc
@@ -452,6 +452,7 @@ LEFDEFReaderOptionsEditor::commit (db::FormatSpecificReaderOptions *options, con
   data->set_labels_suffix (tl::to_string (suffix_labels->text ()));
   data->set_labels_datatype (datatype_labels->text ().toInt ());
   data->set_separate_groups (separate_groups->isChecked ());
+  data->set_read_lef_with_def (read_lef_with_def->isChecked ());
   data->set_map_file (tl::to_string (mapfile_path->text ()));
   data->set_macro_resolution_mode (produce_lef_geo->isChecked () ? 0 : 2);
 
@@ -514,6 +515,7 @@ LEFDEFReaderOptionsEditor::setup (const db::FormatSpecificReaderOptions *options
   suffix_labels->setText (tl::to_qstring (data->labels_suffix ()));
   datatype_labels->setText (QString::number (data->labels_datatype ()));
   separate_groups->setChecked (data->separate_groups ());
+  read_lef_with_def->setChecked (data->read_lef_with_def ());
   mapfile_path->setText (tl::to_qstring (data->map_file ()));
   layer_map_mode->setCurrentIndex (data->map_file ().empty () ? 1 : 0);
   produce_lef_geo->setChecked (data->macro_resolution_mode () == 0);
diff --git a/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFImportTests.cc b/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFImportTests.cc
index dd60edf1c..b4c8a1f8e 100644
--- a/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFImportTests.cc
+++ b/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFImportTests.cc
@@ -27,6 +27,7 @@
 #include "dbLEFImporter.h"
 
 #include "tlUnitTest.h"
+#include "dbTestSupport.h"
 
 #include <cstdlib>
 
@@ -527,3 +528,48 @@ TEST(114_lef_skips_end_library)
   run_test (_this, "lef-skips-end-library", "lef:in.lef+def:in.def", "au.oas", opt, false);
 }
 
+TEST(200_lefdef_plugin)
+{
+  db::Layout ly;
+
+  std::string fn_path (tl::testsrc ());
+  fn_path += "/testdata/lefdef/masks-1/";
+
+  db::LEFDEFReaderOptions lefdef_opt = default_options ();
+  lefdef_opt.set_map_file ("in.map");
+  db::LoadLayoutOptions opt;
+  opt.set_options (lefdef_opt);
+
+  {
+    tl::InputStream is (fn_path + "in.def");
+    db::Reader reader (is);
+    reader.read (ly, opt);
+  }
+
+  db::compare_layouts (_this, ly, fn_path + "au_plugin_def.oas.gz", db::WriteOAS);
+}
+
+TEST(201_lefdef_plugin_explicit_lef)
+{
+  db::Layout ly;
+
+  std::string fn_path (tl::testsrc ());
+  fn_path += "/testdata/lefdef/masks-1/";
+
+  db::LEFDEFReaderOptions lefdef_opt = default_options ();
+  lefdef_opt.set_map_file ("in.map");
+  std::vector<std::string> lf;
+  lf.push_back ("hidden/in_tech.lef");
+  lefdef_opt.set_lef_files (lf);
+  lefdef_opt.set_read_lef_with_def (false);
+  db::LoadLayoutOptions opt;
+  opt.set_options (lefdef_opt);
+
+  {
+    tl::InputStream is (fn_path + "in.def");
+    db::Reader reader (is);
+    reader.read (ly, opt);
+  }
+
+  db::compare_layouts (_this, ly, fn_path + "au_plugin_alt_lef.oas.gz", db::WriteOAS);
+}
diff --git a/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFReaderOptionsTests.cc b/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFReaderOptionsTests.cc
index 7862352bc..9018a98c8 100644
--- a/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFReaderOptionsTests.cc
+++ b/src/plugins/streamers/lefdef/unit_tests/dbLEFDEFReaderOptionsTests.cc
@@ -312,6 +312,10 @@ TEST(1)
   EXPECT_EQ (options.lef_files ().size (), size_t (1));
   EXPECT_EQ (*options.begin_lef_files (), "ABC.lef");
 
+  EXPECT_EQ (options.read_lef_with_def (), true);
+  options.set_read_lef_with_def (false);
+  EXPECT_EQ (options.read_lef_with_def (), false);
+
 
   options.set_map_file ("ABC.map");
   EXPECT_EQ (options.map_file (), "ABC.map");
diff --git a/testdata/lefdef/masks-1/au.oas.gz b/testdata/lefdef/masks-1/au.oas.gz
index 579a0bc45..4d8805a01 100644
Binary files a/testdata/lefdef/masks-1/au.oas.gz and b/testdata/lefdef/masks-1/au.oas.gz differ
diff --git a/testdata/lefdef/masks-1/au_map.oas.gz b/testdata/lefdef/masks-1/au_map.oas.gz
index 45638cae1..dd9c9bc00 100644
Binary files a/testdata/lefdef/masks-1/au_map.oas.gz and b/testdata/lefdef/masks-1/au_map.oas.gz differ
diff --git a/testdata/lefdef/masks-1/au_plugin_alt_lef.oas.gz b/testdata/lefdef/masks-1/au_plugin_alt_lef.oas.gz
new file mode 100644
index 000000000..9f2f877cc
Binary files /dev/null and b/testdata/lefdef/masks-1/au_plugin_alt_lef.oas.gz differ
diff --git a/testdata/lefdef/masks-1/au_plugin_def.oas.gz b/testdata/lefdef/masks-1/au_plugin_def.oas.gz
new file mode 100644
index 000000000..dd9c9bc00
Binary files /dev/null and b/testdata/lefdef/masks-1/au_plugin_def.oas.gz differ
diff --git a/testdata/lefdef/masks-1/hidden/in_tech.lef b/testdata/lefdef/masks-1/hidden/in_tech.lef
new file mode 100644
index 000000000..8a06777ad
--- /dev/null
+++ b/testdata/lefdef/masks-1/hidden/in_tech.lef
@@ -0,0 +1,32 @@
+LAYER M0PO 
+    TYPE MASTERSLICE ;
+    WIDTH 0.02 ;
+    MASKS 2 ;
+END M0PO
+LAYER VIA0
+    TYPE CUT ;
+    MASKS 2 ;
+END VIA0
+LAYER M1
+    TYPE MASTERSLICE ;
+    WIDTH 0.024 ;
+    MASKS 2 ;
+END M1
+LAYER VIA1
+    TYPE CUT ;
+    MASKS 2 ;
+END VIA1
+LAYER M2
+    TYPE MASTERSLICE ;
+    WIDTH 0.03 ;
+    MASKS 2 ;
+END M2
+
+VIA square 
+    LAYER M0PO ;
+        RECT -0.08 -0.08 0.08 0.08 ;
+    LAYER VIA0 ;
+        RECT -0.08 -0.08 0.08 0.08 ;
+    LAYER M1 ;
+        RECT -0.08 -0.08 0.08 0.08 ;
+END square
diff --git a/testdata/lefdef/masks-1/in_tech.lef b/testdata/lefdef/masks-1/in_tech.lef
index c794d34d5..4d7c3fc47 100644
--- a/testdata/lefdef/masks-1/in_tech.lef
+++ b/testdata/lefdef/masks-1/in_tech.lef
@@ -9,7 +9,7 @@ LAYER VIA0
 END VIA0
 LAYER M1
     TYPE MASTERSLICE ;
-    WIDTH 0.025 ;
+    WIDTH 0.024 ;
     MASKS 2 ;
 END M1
 LAYER VIA1
diff --git a/testdata/ruby/dbReaders.rb b/testdata/ruby/dbReaders.rb
index eb33d4c61..f96956f99 100644
--- a/testdata/ruby/dbReaders.rb
+++ b/testdata/ruby/dbReaders.rb
@@ -353,6 +353,10 @@ class DBReaders_TestClass < TestBase
     conf.lef_files = [ "u.lef", "v.lef" ]
     assert_equal(conf.lef_files.join(","), "u.lef,v.lef")
 
+    assert_equal(conf.read_lef_with_def, true)
+    conf.read_lef_with_def = false
+    assert_equal(conf.read_lef_with_def, false)
+
   end
 
   # MAG Options