diff --git a/tests/scripts/check-files.py b/tests/scripts/check-files.py
index 5bec6db..b6fa989 100755
--- a/tests/scripts/check-files.py
+++ b/tests/scripts/check-files.py
@@ -233,6 +233,7 @@
 
     heading = "Tabs present:"
     suffix_exemptions = frozenset([
+        ".pem", # some openssl dumps have tabs
         ".sln",
         "/Makefile",
         "/Makefile.inc",