diff --git a/.style_ignored_dirs b/.style_ignored_dirs
new file mode 100644
index 000000000..4be8efa05
--- /dev/null
+++ b/.style_ignored_dirs
@@ -0,0 +1,4 @@
+# Skip those directories while doing style checks in the CI. Do not add '/' at
+# the beginning!
+
+ext/tinycrypt