diff --git a/basis/unix/statfs/linux/tags.txt b/basis/unix/statfs/linux/tags.txt
new file mode 100644
index 0000000000..6bf68304bb
--- /dev/null
+++ b/basis/unix/statfs/linux/tags.txt
@@ -0,0 +1 @@
+unportable
diff --git a/basis/unix/statfs/macosx/tags.txt b/basis/unix/statfs/macosx/tags.txt
new file mode 100644
index 0000000000..6bf68304bb
--- /dev/null
+++ b/basis/unix/statfs/macosx/tags.txt
@@ -0,0 +1 @@
+unportable