diff --git a/cells/fill/sky130_fd_sc_ms__fill_1.lef b/cells/fill/sky130_fd_sc_ms__fill_1.lef
index d22ee21..c598b06 100644
--- a/cells/fill/sky130_fd_sc_ms__fill_1.lef
+++ b/cells/fill/sky130_fd_sc_ms__fill_1.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_ms__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_ms__fill_1.magic.lef b/cells/fill/sky130_fd_sc_ms__fill_1.magic.lef
index 3f157c0..62b365b 100644
--- a/cells/fill/sky130_fd_sc_ms__fill_1.magic.lef
+++ b/cells/fill/sky130_fd_sc_ms__fill_1.magic.lef
@@ -22,7 +22,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_ms__fill_1
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   FOREIGN sky130_fd_sc_ms__fill_1 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.480000 BY  3.330000 ;
diff --git a/cells/fill/sky130_fd_sc_ms__fill_2.lef b/cells/fill/sky130_fd_sc_ms__fill_2.lef
index 3607e9a..e383251 100644
--- a/cells/fill/sky130_fd_sc_ms__fill_2.lef
+++ b/cells/fill/sky130_fd_sc_ms__fill_2.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_ms__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_ms__fill_2.magic.lef b/cells/fill/sky130_fd_sc_ms__fill_2.magic.lef
index 6b4c1cb..a787190 100644
--- a/cells/fill/sky130_fd_sc_ms__fill_2.magic.lef
+++ b/cells/fill/sky130_fd_sc_ms__fill_2.magic.lef
@@ -22,7 +22,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_ms__fill_2
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   FOREIGN sky130_fd_sc_ms__fill_2 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  0.960000 BY  3.330000 ;
diff --git a/cells/fill/sky130_fd_sc_ms__fill_4.lef b/cells/fill/sky130_fd_sc_ms__fill_4.lef
index 4981883..fe44f4c 100644
--- a/cells/fill/sky130_fd_sc_ms__fill_4.lef
+++ b/cells/fill/sky130_fd_sc_ms__fill_4.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_ms__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_ms__fill_4.magic.lef b/cells/fill/sky130_fd_sc_ms__fill_4.magic.lef
index 8323c8f..78b813a 100644
--- a/cells/fill/sky130_fd_sc_ms__fill_4.magic.lef
+++ b/cells/fill/sky130_fd_sc_ms__fill_4.magic.lef
@@ -22,7 +22,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_ms__fill_4
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   FOREIGN sky130_fd_sc_ms__fill_4 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  1.920000 BY  3.330000 ;
diff --git a/cells/fill/sky130_fd_sc_ms__fill_8.lef b/cells/fill/sky130_fd_sc_ms__fill_8.lef
index d4a01a5..3ca4340 100644
--- a/cells/fill/sky130_fd_sc_ms__fill_8.lef
+++ b/cells/fill/sky130_fd_sc_ms__fill_8.lef
@@ -19,7 +19,7 @@
 BUSBITCHARS "[]" ;
 DIVIDERCHAR "/" ;
 MACRO sky130_fd_sc_ms__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_ms__fill_8.magic.lef b/cells/fill/sky130_fd_sc_ms__fill_8.magic.lef
index d889ff0..d4bc657 100644
--- a/cells/fill/sky130_fd_sc_ms__fill_8.magic.lef
+++ b/cells/fill/sky130_fd_sc_ms__fill_8.magic.lef
@@ -22,7 +22,7 @@
   DATABASE MICRONS 200 ;
 END UNITS
 MACRO sky130_fd_sc_ms__fill_8
-  CLASS CORE ;
+  CLASS CORE SPACER ;
   FOREIGN sky130_fd_sc_ms__fill_8 ;
   ORIGIN  0.000000  0.000000 ;
   SIZE  3.840000 BY  3.330000 ;