diff --git a/VERSION b/VERSION
index 5726fec..d5e8122 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.0.507
+1.0.508
diff --git a/sky130/custom/scripts/rename_cells.py b/sky130/custom/scripts/rename_cells.py
index 2576bee..66642c8 100755
--- a/sky130/custom/scripts/rename_cells.py
+++ b/sky130/custom/scripts/rename_cells.py
@@ -40,8 +40,8 @@
     for line in spilines:
 
         # These substitutions are for files originating from cells/*/*.spice
-        fixedline = re.sub('\.\./\.\./models/', '../../../libs.tech/ngspice/', line)
-        fixedline = re.sub('\.\./[^/\.]+/', '', fixedline)
+        fixedline = re.sub(r'\.\./\.\./models/', '../../../libs.tech/ngspice/', line)
+        fixedline = re.sub(r'\.\./[^/\.]+/', '', fixedline)
         fixedlines.append(fixedline)
         if fixedline != line:
             modified = True