diff --git a/cells/tap/sky130_fd_sc_ms__tap_1.lef b/cells/tap/sky130_fd_sc_ms__tap_1.lef
index fa4fc29..c328677 100644
--- a/cells/tap/sky130_fd_sc_ms__tap_1.lef
+++ b/cells/tap/sky130_fd_sc_ms__tap_1.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_ms__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_ms__tap_1.magic.lef b/cells/tap/sky130_fd_sc_ms__tap_1.magic.lef
index 5bae8bb..ac26919 100644
--- a/cells/tap/sky130_fd_sc_ms__tap_1.magic.lef
+++ b/cells/tap/sky130_fd_sc_ms__tap_1.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_ms__tap_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   FOREIGN sky130_fd_sc_ms__tap_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/tap/sky130_fd_sc_ms__tap_2.lef b/cells/tap/sky130_fd_sc_ms__tap_2.lef
index 76df035..c2d00d4 100644
--- a/cells/tap/sky130_fd_sc_ms__tap_2.lef
+++ b/cells/tap/sky130_fd_sc_ms__tap_2.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_ms__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_ms__tap_2.magic.lef b/cells/tap/sky130_fd_sc_ms__tap_2.magic.lef
index d24734b..600413f 100644
--- a/cells/tap/sky130_fd_sc_ms__tap_2.magic.lef
+++ b/cells/tap/sky130_fd_sc_ms__tap_2.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_ms__tap_2
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   FOREIGN sky130_fd_sc_ms__tap_2 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;
diff --git a/cells/tapmet1/sky130_fd_sc_ms__tapmet1_2.lef b/cells/tapmet1/sky130_fd_sc_ms__tapmet1_2.lef
index eb79fc4..fa10732 100644
--- a/cells/tapmet1/sky130_fd_sc_ms__tapmet1_2.lef
+++ b/cells/tapmet1/sky130_fd_sc_ms__tapmet1_2.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_ms__tapmet1_2
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;
diff --git a/cells/tapmet1/sky130_fd_sc_ms__tapmet1_2.magic.lef b/cells/tapmet1/sky130_fd_sc_ms__tapmet1_2.magic.lef
index 4c486c8..0215994 100644
--- a/cells/tapmet1/sky130_fd_sc_ms__tapmet1_2.magic.lef
+++ b/cells/tapmet1/sky130_fd_sc_ms__tapmet1_2.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_ms__tapmet1_2
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   FOREIGN sky130_fd_sc_ms__tapmet1_2 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;
diff --git a/cells/tapvgnd/sky130_fd_sc_ms__tapvgnd_1.lef b/cells/tapvgnd/sky130_fd_sc_ms__tapvgnd_1.lef
index db20024..00538cc 100644
--- a/cells/tapvgnd/sky130_fd_sc_ms__tapvgnd_1.lef
+++ b/cells/tapvgnd/sky130_fd_sc_ms__tapvgnd_1.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_ms__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_ms__tapvgnd_1.magic.lef b/cells/tapvgnd/sky130_fd_sc_ms__tapvgnd_1.magic.lef
index a2cc723..b9e5648 100644
--- a/cells/tapvgnd/sky130_fd_sc_ms__tapvgnd_1.magic.lef
+++ b/cells/tapvgnd/sky130_fd_sc_ms__tapvgnd_1.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_ms__tapvgnd_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   FOREIGN sky130_fd_sc_ms__tapvgnd_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/tapvgnd2/sky130_fd_sc_ms__tapvgnd2_1.lef b/cells/tapvgnd2/sky130_fd_sc_ms__tapvgnd2_1.lef
index 895559d..c7964fc 100644
--- a/cells/tapvgnd2/sky130_fd_sc_ms__tapvgnd2_1.lef
+++ b/cells/tapvgnd2/sky130_fd_sc_ms__tapvgnd2_1.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_ms__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_ms__tapvgnd2_1.magic.lef b/cells/tapvgnd2/sky130_fd_sc_ms__tapvgnd2_1.magic.lef
index d2dea1a..96c1cc4 100644
--- a/cells/tapvgnd2/sky130_fd_sc_ms__tapvgnd2_1.magic.lef
+++ b/cells/tapvgnd2/sky130_fd_sc_ms__tapvgnd2_1.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_ms__tapvgnd2_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   FOREIGN sky130_fd_sc_ms__tapvgnd2_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/tapvpwrvgnd/sky130_fd_sc_ms__tapvpwrvgnd_1.lef b/cells/tapvpwrvgnd/sky130_fd_sc_ms__tapvpwrvgnd_1.lef
index 38af0ff..2b99b50 100644
--- a/cells/tapvpwrvgnd/sky130_fd_sc_ms__tapvpwrvgnd_1.lef
+++ b/cells/tapvpwrvgnd/sky130_fd_sc_ms__tapvpwrvgnd_1.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_ms__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_ms__tapvpwrvgnd_1.magic.lef b/cells/tapvpwrvgnd/sky130_fd_sc_ms__tapvpwrvgnd_1.magic.lef
index 0e59586..de12a35 100644
--- a/cells/tapvpwrvgnd/sky130_fd_sc_ms__tapvpwrvgnd_1.magic.lef
+++ b/cells/tapvpwrvgnd/sky130_fd_sc_ms__tapvpwrvgnd_1.magic.lef
@@ -23,7 +23,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_ms__tapvpwrvgnd_1
-  CLASS CORE ;
+  CLASS CORE WELLTAP ;
   FOREIGN sky130_fd_sc_ms__tapvpwrvgnd_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;