diff --git a/cells/conb/sky130_fd_sc_lp__conb_0.lef b/cells/conb/sky130_fd_sc_lp__conb_0.lef
index e80a40f..ad6180d 100644
--- a/cells/conb/sky130_fd_sc_lp__conb_0.lef
+++ b/cells/conb/sky130_fd_sc_lp__conb_0.lef
@@ -19,7 +19,8 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_lp__conb_0
-  CLASS CORE ;
+  CLASS CORE TIELOW ;
+  CLASS CORE TIEHIGH ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  1.440000 BY  3.330000 ;
diff --git a/cells/conb/sky130_fd_sc_lp__conb_0.magic.lef b/cells/conb/sky130_fd_sc_lp__conb_0.magic.lef
index 486feb3..ac375b4 100644
--- a/cells/conb/sky130_fd_sc_lp__conb_0.magic.lef
+++ b/cells/conb/sky130_fd_sc_lp__conb_0.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_lp__conb_0
-  CLASS CORE ;
+  CLASS CORE TIEHIGH ;
   FOREIGN sky130_fd_sc_lp__conb_0 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  1.440000 BY  3.330000 ;
diff --git a/cells/conb/sky130_fd_sc_lp__conb_1.lef b/cells/conb/sky130_fd_sc_lp__conb_1.lef
index f9ac7bb..ebfad64 100644
--- a/cells/conb/sky130_fd_sc_lp__conb_1.lef
+++ b/cells/conb/sky130_fd_sc_lp__conb_1.lef
@@ -19,7 +19,8 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_lp__conb_1
-  CLASS CORE ;
+  CLASS CORE TIELOW ;
+  CLASS CORE TIEHIGH ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  1.440000 BY  3.330000 ;
diff --git a/cells/conb/sky130_fd_sc_lp__conb_1.magic.lef b/cells/conb/sky130_fd_sc_lp__conb_1.magic.lef
index 22e44c0..98c6302 100644
--- a/cells/conb/sky130_fd_sc_lp__conb_1.magic.lef
+++ b/cells/conb/sky130_fd_sc_lp__conb_1.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_lp__conb_1
-  CLASS CORE ;
+  CLASS CORE TIEHIGH ;
   FOREIGN sky130_fd_sc_lp__conb_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  1.440000 BY  3.330000 ;
diff --git a/cells/tap/sky130_fd_sc_lp__tap_1.lef b/cells/tap/sky130_fd_sc_lp__tap_1.lef
index f14bfcc..ee24add 100644
--- a/cells/tap/sky130_fd_sc_lp__tap_1.lef
+++ b/cells/tap/sky130_fd_sc_lp__tap_1.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_lp__tap_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/tap/sky130_fd_sc_lp__tap_1.magic.lef b/cells/tap/sky130_fd_sc_lp__tap_1.magic.lef
index b12a563..30f4bdd 100644
--- a/cells/tap/sky130_fd_sc_lp__tap_1.magic.lef
+++ b/cells/tap/sky130_fd_sc_lp__tap_1.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_lp__tap_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   FOREIGN sky130_fd_sc_lp__tap_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/tap/sky130_fd_sc_lp__tap_2.lef b/cells/tap/sky130_fd_sc_lp__tap_2.lef
index c16e22a..b98ab4d 100644
--- a/cells/tap/sky130_fd_sc_lp__tap_2.lef
+++ b/cells/tap/sky130_fd_sc_lp__tap_2.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_lp__tap_2
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;
diff --git a/cells/tap/sky130_fd_sc_lp__tap_2.magic.lef b/cells/tap/sky130_fd_sc_lp__tap_2.magic.lef
index ba8b292..8421513 100644
--- a/cells/tap/sky130_fd_sc_lp__tap_2.magic.lef
+++ b/cells/tap/sky130_fd_sc_lp__tap_2.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_lp__tap_2
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   FOREIGN sky130_fd_sc_lp__tap_2 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;
diff --git a/cells/tapvgnd/sky130_fd_sc_lp__tapvgnd_1.lef b/cells/tapvgnd/sky130_fd_sc_lp__tapvgnd_1.lef
index a452d3b..1a77626 100644
--- a/cells/tapvgnd/sky130_fd_sc_lp__tapvgnd_1.lef
+++ b/cells/tapvgnd/sky130_fd_sc_lp__tapvgnd_1.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_lp__tapvgnd_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/tapvgnd/sky130_fd_sc_lp__tapvgnd_1.magic.lef b/cells/tapvgnd/sky130_fd_sc_lp__tapvgnd_1.magic.lef
index 95031c6..9f088a6 100644
--- a/cells/tapvgnd/sky130_fd_sc_lp__tapvgnd_1.magic.lef
+++ b/cells/tapvgnd/sky130_fd_sc_lp__tapvgnd_1.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_lp__tapvgnd_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   FOREIGN sky130_fd_sc_lp__tapvgnd_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/tapvgnd2/sky130_fd_sc_lp__tapvgnd2_1.lef b/cells/tapvgnd2/sky130_fd_sc_lp__tapvgnd2_1.lef
index c182914..78d7b72 100644
--- a/cells/tapvgnd2/sky130_fd_sc_lp__tapvgnd2_1.lef
+++ b/cells/tapvgnd2/sky130_fd_sc_lp__tapvgnd2_1.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_lp__tapvgnd2_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/tapvgnd2/sky130_fd_sc_lp__tapvgnd2_1.magic.lef b/cells/tapvgnd2/sky130_fd_sc_lp__tapvgnd2_1.magic.lef
index e26e265..4d1ad1b 100644
--- a/cells/tapvgnd2/sky130_fd_sc_lp__tapvgnd2_1.magic.lef
+++ b/cells/tapvgnd2/sky130_fd_sc_lp__tapvgnd2_1.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_lp__tapvgnd2_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   FOREIGN sky130_fd_sc_lp__tapvgnd2_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/tapvpwrvgnd/sky130_fd_sc_lp__tapvpwrvgnd_1.lef b/cells/tapvpwrvgnd/sky130_fd_sc_lp__tapvpwrvgnd_1.lef
index 6cfc32f..fe18077 100644
--- a/cells/tapvpwrvgnd/sky130_fd_sc_lp__tapvpwrvgnd_1.lef
+++ b/cells/tapvpwrvgnd/sky130_fd_sc_lp__tapvpwrvgnd_1.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_lp__tapvpwrvgnd_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/tapvpwrvgnd/sky130_fd_sc_lp__tapvpwrvgnd_1.magic.lef b/cells/tapvpwrvgnd/sky130_fd_sc_lp__tapvpwrvgnd_1.magic.lef
index 4ce2843..8f5806d 100644
--- a/cells/tapvpwrvgnd/sky130_fd_sc_lp__tapvpwrvgnd_1.magic.lef
+++ b/cells/tapvpwrvgnd/sky130_fd_sc_lp__tapvpwrvgnd_1.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_lp__tapvpwrvgnd_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   FOREIGN sky130_fd_sc_lp__tapvpwrvgnd_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;