diff --git a/ibis/target/CACHEDIR.TAG b/ibis/target/CACHEDIR.TAG
new file mode 100644
index 000000000..20d7c319c
--- /dev/null
+++ b/ibis/target/CACHEDIR.TAG
@@ -0,0 +1,3 @@
+Signature: 8a477f597d28d172789f06886806bc55
+# This file is a cache directory tag created by cargo.
+# For information about cache directory tags see https://bford.info/cachedir/