diff --git a/src/hash-utils.rkt b/src/hash-utils.rkt
new file mode 100644
index 0000000..d551ae4
--- /dev/null
+++ b/src/hash-utils.rkt
@@ -0,0 +1,12 @@
+#lang racket/base
+
+(provide @
+         @ref)
+
+(define-syntax @
+  (syntax-rules ()
+    [(_ v) v]
+    [(_ v k rest ...) (@ (@ref v 'k) rest ...)]))
+
+(define (@ref v k)
+  (and v (hash-ref v k (lambda () #f))))
diff --git a/src/packages.rkt b/src/packages.rkt
index 70409f7..0f6b629 100644
--- a/src/packages.rkt
+++ b/src/packages.rkt
@@ -1,8 +1,6 @@
 #lang racket/base
 
-(provide @
-         @ref
-         all-package-names
+(provide all-package-names
          all-tags
          all-formal-tags
          sorted-package-names
@@ -29,16 +27,7 @@
 (require reloadable)
 (require "config.rkt")
 (require "daemon.rkt")
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-
-(define-syntax @
-  (syntax-rules ()
-    [(_ v) v]
-    [(_ v k rest ...) (@ (@ref v 'k) rest ...)]))
-
-(define (@ref v k)
-  (and v (hash-ref v k (lambda () #f))))
+(require "hash-utils.rkt")
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
diff --git a/src/sessions.rkt b/src/sessions.rkt
index 4a2a6a3..5618c4f 100644
--- a/src/sessions.rkt
+++ b/src/sessions.rkt
@@ -11,11 +11,12 @@
 
 (require "randomness.rkt")
 (require "config.rkt")
+(require "hash-utils.rkt")
 (require reloadable)
 
 (define current-session (make-parameter #f))
 (define session-lifetime
-  (* (or (hash-ref (config) 'session-lifetime-seconds #f)
+  (* (or (@ (config) session-lifetime-seconds)
          (* 7 24 60 60)) ;; one week in seconds
      1000)) ;; convert to milliseconds
 
diff --git a/src/site.rkt b/src/site.rkt
index 1564730..ddfd404 100644
--- a/src/site.rkt
+++ b/src/site.rkt
@@ -23,6 +23,7 @@
 (require reloadable)
 (require "daemon.rkt")
 (require "config.rkt")
+(require "hash-utils.rkt")
 
 (define static-cached-directory
   (or (@ (config) static-cached-directory)