diff --git a/run-drc-for-cell-gds-using-magic/action.yml b/run-drc-for-cell-gds-using-magic/action.yml
index d7b39d6..1a842d2 100644
--- a/run-drc-for-cell-gds-using-magic/action.yml
+++ b/run-drc-for-cell-gds-using-magic/action.yml
@@ -31,7 +31,7 @@
   match-directories:
     description: >-
         A regex that will match subdirectories under cells to be checked.
-    default: .*
+    default: ^.*$
   known-bad:
     description: >-
         List of known bad cells that should be ignored.
diff --git a/run-drc-for-cell-gds-using-magic/run_all_drc.py b/run-drc-for-cell-gds-using-magic/run_all_drc.py
index 9ba9605..7ca18bb 100644
--- a/run-drc-for-cell-gds-using-magic/run_all_drc.py
+++ b/run-drc-for-cell-gds-using-magic/run_all_drc.py
@@ -151,7 +151,7 @@
 @click.option(
     "-m",
     "--match-directories",
-    default=".",
+    default="^.*$",
     help="A regex that will match subdirectories under cells/."
          " Default: . (matches everything.)"
 )
@@ -182,7 +182,7 @@
         cells = os.listdir(cells_dir)
 
         for cell in cells:
-            if not re.match(match_directories, cell):
+            if not re.fullmatch(match_directories, cell):
                 print("Skipping directory %s…" % cell)
                 continue