diff --git a/core/siren-core-editor.el b/core/siren-core-editor.el
index c48723a..044e0d7 100644
--- a/core/siren-core-editor.el
+++ b/core/siren-core-editor.el
@@ -28,7 +28,7 @@
 (setq sentence-end-double-space nil)
 
 ;; Save place in files
-(setq save-place-file (expand-file-name "saveplace" siren-cache-dir))
+(setq save-place-file (siren-cache-dir "saveplace"))
 (save-place-mode 1)
 
 ;; Electric behavior
@@ -51,11 +51,10 @@
       kept-old-versions 0
       vc-make-backup-files t
       version-control t
-      backup-directory-alist
-      `((".*" . ,(expand-file-name "backup" siren-cache-dir))))
+      backup-directory-alist `((".*" . ,(siren-cache-dir "backup"))))
 
 ;; Auto-save files
-(let ((auto-save-dir (expand-file-name "autosave/" siren-cache-dir)))
+(let ((auto-save-dir (siren-cache-dir "autosave/")))
   (unless (file-exists-p auto-save-dir)
     (make-directory auto-save-dir))
   (setq auto-save-interval 20
diff --git a/core/siren-core-init.el b/core/siren-core-init.el
index fe53ec4..795db56 100644
--- a/core/siren-core-init.el
+++ b/core/siren-core-init.el
@@ -33,6 +33,14 @@
 (unless (file-exists-p siren-cache-dir)
   (make-directory siren-cache-dir))
 
+(defun siren-dir (name)
+  "Return absolute path to sub-directory NAME under siren-dir."
+  (expand-file-name name siren-dir))
+
+(defun siren-cache-dir (name)
+  "Return absolute path to sub-directory NAME under siren-cache-dir."
+  (expand-file-name name siren-cache-dir))
+
 ;; Setup load-path
 (add-to-list 'load-path siren-core-dir)
 
@@ -57,7 +65,7 @@
   (require 'siren-core-linux))
 
 ;; Config changes made through the customize UI will be store here
-(setq custom-file (expand-file-name "custom.el" siren-dir))
+(setq custom-file (siren-dir "custom.el"))
 (load-file custom-file)
 
 ;; Enable custom themes
diff --git a/core/siren-core-modules.el b/core/siren-core-modules.el
index fa82fcb..ed79e1d 100644
--- a/core/siren-core-modules.el
+++ b/core/siren-core-modules.el
@@ -6,7 +6,7 @@
 
 ;;; Code:
 
-(defvar siren-modules-dir (expand-file-name "modules" siren-dir)
+(defvar siren-modules-dir (siren-dir "modules")
   "Root directory for Emacs Siren modules.")
 (siren-recursive-add-to-load-path siren-modules-dir)
 
diff --git a/core/siren-core-themes.el b/core/siren-core-themes.el
index ffc4921..31ad04a 100644
--- a/core/siren-core-themes.el
+++ b/core/siren-core-themes.el
@@ -6,7 +6,7 @@
 
 ;;; Code:
 
-(defvar siren-themes-dir (expand-file-name "themes" siren-dir)
+(defvar siren-themes-dir (siren-dir "themes")
   "Root directory for Emacs Siren custom themes.")
 (add-to-list 'custom-theme-load-path siren-themes-dir)
 
diff --git a/modules/editor/siren-amx.el b/modules/editor/siren-amx.el
index 097d2b4..2142012 100644
--- a/modules/editor/siren-amx.el
+++ b/modules/editor/siren-amx.el
@@ -17,7 +17,7 @@
   (amx-backend 'ido)
   (amx-histroy-lenth 15)
   (amx-prompt-string "M-x ")
-  (amx-save-file (expand-file-name "amx-items" siren-cache-dir))
+  (amx-save-file (siren-cache-dir "amx-items"))
   (amx-show-key-bindings t)
 
   :config
diff --git a/modules/editor/siren-ido.el b/modules/editor/siren-ido.el
index 5a8e38d..9e4ab4f 100644
--- a/modules/editor/siren-ido.el
+++ b/modules/editor/siren-ido.el
@@ -17,7 +17,7 @@
   (ido-enable-flex-matching t)
   (ido-enable-prefix nil)
   (ido-max-prospects 12)
-  (ido-save-directory-list-file (expand-file-name "ido.hist" siren-cache-dir))
+  (ido-save-directory-list-file (siren-cache-dir "ido.hist"))
   (ido-use-faces t)
   (ido-use-filename-at-point nil)
 
diff --git a/modules/editor/siren-prescient.el b/modules/editor/siren-prescient.el
index 628ae4c..5fcae63 100644
--- a/modules/editor/siren-prescient.el
+++ b/modules/editor/siren-prescient.el
@@ -12,7 +12,7 @@
   :custom
   (prescient-filter-method '(literal-prefix literal regexp initialism fuzzy))
   (prescient-history-length 100)
-  (prescient-save-file (expand-file-name "prescient-save.el" siren-cache-dir))
+  (prescient-save-file (siren-cache-dir "prescient-save.el"))
   (prescient-sort-full-matches-first t)
   (prescient-sort-length-enable nil)
 
diff --git a/modules/editor/siren-recentf.el b/modules/editor/siren-recentf.el
index f6ac467..c3f1aa9 100644
--- a/modules/editor/siren-recentf.el
+++ b/modules/editor/siren-recentf.el
@@ -11,7 +11,7 @@
   :demand t
 
   :custom
-  (recentf-save-file (expand-file-name "recentf" siren-cache-dir))
+  (recentf-save-file (siren-cache-dir "recentf"))
   (recentf-max-saved-items 5000)
   (recentf-max-menu-items 1000)
   (recentf-auto-cleanup 'never)
diff --git a/modules/editor/siren-savehist.el b/modules/editor/siren-savehist.el
index 0a6d285..76d61e1 100644
--- a/modules/editor/siren-savehist.el
+++ b/modules/editor/siren-savehist.el
@@ -12,7 +12,7 @@
   :custom
   (savehist-additional-variables '(search-ring regexp-search-ring))
   (savehist-autosave-interval 60)
-  (savehist-file (expand-file-name "savehist" siren-cache-dir))
+  (savehist-file (siren-cache-dir "savehist"))
 
   :init
   (savehist-mode +1))
diff --git a/modules/editor/siren-smex.el b/modules/editor/siren-smex.el
index c736571..81c7644 100644
--- a/modules/editor/siren-smex.el
+++ b/modules/editor/siren-smex.el
@@ -14,7 +14,7 @@
   ("C-c C-c M-x" 'execute-extended-command)
 
   :custom
-  (smex-save-file (expand-file-name "smex-items" siren-cache-dir))
+  (smex-save-file (siren-cache-dir "smex-items"))
 
   :config
   (smex-initialize))
diff --git a/modules/editor/siren-undo-tree.el b/modules/editor/siren-undo-tree.el
index 24ebb8d..0021556 100644
--- a/modules/editor/siren-undo-tree.el
+++ b/modules/editor/siren-undo-tree.el
@@ -21,7 +21,7 @@
 
   :custom
   (undo-tree-history-directory-alist
-   `((".*" . ,(expand-file-name "undo-tree-history" siren-cache-dir))))
+   `((".*" . ,(siren-cache-dir "undo-tree-history"))))
   ;; Use undohist package to persist history to disk, it seems more reliable
   ;; than undo-tree's auto-save feature which randomly fails to restore history
   ;; for no obvious reason.
diff --git a/modules/editor/siren-undohist.el b/modules/editor/siren-undohist.el
index 35d185c..6c3730c 100644
--- a/modules/editor/siren-undohist.el
+++ b/modules/editor/siren-undohist.el
@@ -9,7 +9,7 @@
 (use-package undohist
   :demand
   :custom
-  (undohist-directory (expand-file-name "undohist" siren-cache-dir))
+  (undohist-directory (siren-cache-dir "undohist"))
   (undohist-ignored-files '("COMMIT_EDITMSG"))
 
   :config
diff --git a/modules/projects/siren-project-explorer.el b/modules/projects/siren-project-explorer.el
index 48d0847..7928938 100644
--- a/modules/projects/siren-project-explorer.el
+++ b/modules/projects/siren-project-explorer.el
@@ -13,7 +13,7 @@
   :custom
   (pe/follow-current t)
   (pe/width 54)
-  (pe/cache-directory (expand-file-name "project-explorer" siren-cache-dir))
+  (pe/cache-directory (siren-cache-dir "project-explorer"))
 
   :config
   ;; Make Project Explorer open selected file in last used buffer
diff --git a/modules/projects/siren-projectile.el b/modules/projects/siren-projectile.el
index bd79d01..535f035 100644
--- a/modules/projects/siren-projectile.el
+++ b/modules/projects/siren-projectile.el
@@ -27,7 +27,7 @@
 
   :custom
   (projectile-buffers-filter-function 'projectile-buffers-with-file-or-process)
-  (projectile-cache-file (expand-file-name "projectile" siren-cache-dir))
+  (projectile-cache-file (siren-cache-dir "projectile"))
   (projectile-completion-system 'default)
   (projectile-enable-caching nil)
   (projectile-globally-ignored-directories '(".bzr"
diff --git a/modules/projects/siren-treemacs.el b/modules/projects/siren-treemacs.el
index 96c64e3..f6f4673 100644
--- a/modules/projects/siren-treemacs.el
+++ b/modules/projects/siren-treemacs.el
@@ -26,9 +26,9 @@
   (treemacs-sorting 'alphabetic-asc)
   (treemacs-width 40)
 
-  (treemacs-persist-file (expand-file-name "treemacs-persist" siren-cache-dir))
+  (treemacs-persist-file (siren-cache-dir "treemacs-persist"))
   (treemacs-last-error-persist-file
-   (expand-file-name "treemacs-persist-at-last-error" siren-cache-dir))
+   (siren-cache-dir "treemacs-persist-at-last-error"))
 
   :preface
   (defgroup siren-treemacs nil
diff --git a/modules/text-editing/siren-tempel.el b/modules/text-editing/siren-tempel.el
index 6f47146..fe1ef7e 100644
--- a/modules/text-editing/siren-tempel.el
+++ b/modules/text-editing/siren-tempel.el
@@ -15,7 +15,7 @@
             "TAB" 'tempel-next)
 
   :custom
-  (tempel-path (expand-file-name "templates/*.el" siren-dir))
+  (tempel-path (siren-dir "templates/*.el"))
 
   :hook
   (prog-mode . siren-tempel-setup-capf)
diff --git a/modules/version-control/siren-code-review.el b/modules/version-control/siren-code-review.el
index 95c087b..5282f28 100644
--- a/modules/version-control/siren-code-review.el
+++ b/modules/version-control/siren-code-review.el
@@ -9,8 +9,7 @@
 (use-package code-review
   :defer t
   :custom
-  (code-review-db-database-file (expand-file-name
-                                 "code-review-db.sqlite" siren-cache-dir))
+  (code-review-db-database-file (siren-cache-dir "code-review-db.sqlite"))
   (code-review-fill-column 80)
   (code-review-lgtm-message "lgtm :)")
   (code-review-new-buffer-window-strategy 'switch-to-buffer))
diff --git a/modules/version-control/siren-forge.el b/modules/version-control/siren-forge.el
index 4940c38..fcb66d6 100644
--- a/modules/version-control/siren-forge.el
+++ b/modules/version-control/siren-forge.el
@@ -16,8 +16,7 @@
   :after magit
 
   :custom
-  (forge-database-file (expand-file-name
-                        "forge-database.sqlite" siren-cache-dir))
+  (forge-database-file (siren-cache-dir "forge-database.sqlite"))
 
   :config
   (transient-insert-suffix 'forge-dispatch '(1)
diff --git a/modules/version-control/siren-magit.el b/modules/version-control/siren-magit.el
index 487963f..23883db 100644
--- a/modules/version-control/siren-magit.el
+++ b/modules/version-control/siren-magit.el
@@ -59,12 +59,9 @@
 (use-package transient
   :defer t
   :custom
-  (transient-history-file
-   (expand-file-name "transient/history.el" siren-cache-dir))
-  (transient-levels-file
-   (expand-file-name "transient/levels.el" siren-cache-dir))
-  (transient-values-file
-   (expand-file-name "transient/values.el" siren-cache-dir)))
+  (transient-history-file (siren-cache-dir "transient/history.el"))
+  (transient-levels-file (siren-cache-dir "transient/levels.el"))
+  (transient-values-file (siren-cache-dir "transient/values.el")))
 
 (use-package magit-delta
   :hook
diff --git a/modules/workspaces/siren-desktop.el b/modules/workspaces/siren-desktop.el
index f9fb3b3..1917563 100644
--- a/modules/workspaces/siren-desktop.el
+++ b/modules/workspaces/siren-desktop.el
@@ -94,7 +94,7 @@
     (make-directory desktop+-base-dir))
 
   :preface
-  (defvar desktop+-base-dir (expand-file-name "desktops" siren-dir)
+  (defvar desktop+-base-dir (siren-dir "desktops")
     "Base directory for desktop files.")
 
   (defun siren-desktop+-current-desktop ()