diff --git a/strbuf.h b/strbuf.h
index 3dfeadb44c..70778c6e10 100644
--- a/strbuf.h
+++ b/strbuf.h
@@ -1,6 +1,14 @@
 #ifndef STRBUF_H
 #define STRBUF_H
 
+/*
+ * NOTE FOR STRBUF DEVELOPERS
+ *
+ * strbuf is a low-level primitive; as such it should interact only
+ * with other low-level primitives. Do not introduce new functions
+ * which interact with higher-level APIs.
+ */
+
 struct string_list;
 
 /**