diff --git a/cells/fill/sky130_fd_sc_lp__fill_1.lef b/cells/fill/sky130_fd_sc_lp__fill_1.lef
index 6f426db..0b6be32 100644
--- a/cells/fill/sky130_fd_sc_lp__fill_1.lef
+++ b/cells/fill/sky130_fd_sc_lp__fill_1.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_lp__fill_1
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/fill/sky130_fd_sc_lp__fill_1.magic.lef b/cells/fill/sky130_fd_sc_lp__fill_1.magic.lef
index 43a15fa..90cf7f1 100644
--- a/cells/fill/sky130_fd_sc_lp__fill_1.magic.lef
+++ b/cells/fill/sky130_fd_sc_lp__fill_1.magic.lef
@@ -22,7 +22,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_lp__fill_1
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   FOREIGN sky130_fd_sc_lp__fill_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/fill/sky130_fd_sc_lp__fill_2.lef b/cells/fill/sky130_fd_sc_lp__fill_2.lef
index b5abc73..d072f47 100644
--- a/cells/fill/sky130_fd_sc_lp__fill_2.lef
+++ b/cells/fill/sky130_fd_sc_lp__fill_2.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_lp__fill_2
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;
diff --git a/cells/fill/sky130_fd_sc_lp__fill_2.magic.lef b/cells/fill/sky130_fd_sc_lp__fill_2.magic.lef
index d2bb183..28f6684 100644
--- a/cells/fill/sky130_fd_sc_lp__fill_2.magic.lef
+++ b/cells/fill/sky130_fd_sc_lp__fill_2.magic.lef
@@ -22,7 +22,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_lp__fill_2
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   FOREIGN sky130_fd_sc_lp__fill_2 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;
diff --git a/cells/fill/sky130_fd_sc_lp__fill_4.lef b/cells/fill/sky130_fd_sc_lp__fill_4.lef
index e90856d..4b69765 100644
--- a/cells/fill/sky130_fd_sc_lp__fill_4.lef
+++ b/cells/fill/sky130_fd_sc_lp__fill_4.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_lp__fill_4
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  1.920000 BY  3.330000 ;
diff --git a/cells/fill/sky130_fd_sc_lp__fill_4.magic.lef b/cells/fill/sky130_fd_sc_lp__fill_4.magic.lef
index 25cd0c7..d340c9f 100644
--- a/cells/fill/sky130_fd_sc_lp__fill_4.magic.lef
+++ b/cells/fill/sky130_fd_sc_lp__fill_4.magic.lef
@@ -22,7 +22,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_lp__fill_4
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   FOREIGN sky130_fd_sc_lp__fill_4 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  1.920000 BY  3.330000 ;
diff --git a/cells/fill/sky130_fd_sc_lp__fill_8.lef b/cells/fill/sky130_fd_sc_lp__fill_8.lef
index b08da5f..6dca497 100644
--- a/cells/fill/sky130_fd_sc_lp__fill_8.lef
+++ b/cells/fill/sky130_fd_sc_lp__fill_8.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_lp__fill_8
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   SOURCE USER ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  3.840000 BY  3.330000 ;
diff --git a/cells/fill/sky130_fd_sc_lp__fill_8.magic.lef b/cells/fill/sky130_fd_sc_lp__fill_8.magic.lef
index 1fbf47e..e22e1c1 100644
--- a/cells/fill/sky130_fd_sc_lp__fill_8.magic.lef
+++ b/cells/fill/sky130_fd_sc_lp__fill_8.magic.lef
@@ -22,7 +22,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_lp__fill_8
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   FOREIGN sky130_fd_sc_lp__fill_8 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  3.840000 BY  3.330000 ;