diff --git a/scheme/httpd/surflets/surflet-handler.scm b/scheme/httpd/surflets/surflet-handler.scm
index 502cc32..8343fe1 100644
--- a/scheme/httpd/surflets/surflet-handler.scm
+++ b/scheme/httpd/surflets/surflet-handler.scm
@@ -13,6 +13,10 @@
 ;; sets the value (an option record, see end of file)
 (define *options* (make-preserved-thread-fluid #f))
 
+;;; TABLES are thread safe as they all use the same lock and different
+;;; keys for the hash (There may be performance reasons to change
+;;; this, though).
+
 ;;; SURFLET-TABLE cache
 (define *surflet-table* (make-string-table)) ; path-string is index
 (define *surflet-table-lock* (make-lock))
diff --git a/scheme/httpd/surflets/surflets.scm b/scheme/httpd/surflets/surflets.scm
index 5676f17..6e65770 100644
--- a/scheme/httpd/surflets/surflets.scm
+++ b/scheme/httpd/surflets/surflets.scm
@@ -35,8 +35,9 @@
 
 ;; Bindings of POST requests can be read only once, since they are
 ;; read from an input port. So we have to cache them, for the case of
-;; a later GET-BINDINGS call on the same POST request. The request are
-;; referenced by a weak pointer.
+;; a later GET-BINDINGS call on the same POST request. The requests
+;; are referenced by a weak pointer. Thread-safe as all threads use
+;; the same lock.
 (define *POST-bindings-cache* '())
 (define *cache-lock* (make-lock))