diff --git a/cells/conb/sky130_fd_sc_hvl__conb_1.lef b/cells/conb/sky130_fd_sc_hvl__conb_1.lef
index 413b9a4..e3a1ddf 100644
--- a/cells/conb/sky130_fd_sc_hvl__conb_1.lef
+++ b/cells/conb/sky130_fd_sc_hvl__conb_1.lef
@@ -19,7 +19,8 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_hvl__conb_1
-  CLASS CORE ;
+  CLASS CORE TIELOW ;
+  CLASS CORE TIEHIGH ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  2.400000 BY  4.070000 ;
diff --git a/cells/conb/sky130_fd_sc_hvl__conb_1.magic.lef b/cells/conb/sky130_fd_sc_hvl__conb_1.magic.lef
index b2c14f5..114e2b7 100644
--- a/cells/conb/sky130_fd_sc_hvl__conb_1.magic.lef
+++ b/cells/conb/sky130_fd_sc_hvl__conb_1.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_hvl__conb_1
-  CLASS CORE ;
+  CLASS CORE TIEHIGH ;
   FOREIGN sky130_fd_sc_hvl__conb_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  2.400000 BY  4.070000 ;