diff --git a/observation/src/ttysnoop/ttysnoop.h b/observation/src/ttysnoop/ttysnoop.h
new file mode 100644
index 0000000000000000000000000000000000000000..f54a7e52d1505e3711ee2170a28aa9908714b3ef
--- /dev/null
+++ b/observation/src/ttysnoop/ttysnoop.h
@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
+#ifndef __TTYSNOOP_H
+#define __TTYSNOOP_H
+
+#define BUFSIZE		256
+
+struct event {
+	char buf[BUFSIZE+1];
+	size_t count;
+};
+
+#endif
+