diff --git a/lisp/cli/packages.el b/lisp/cli/packages.el
index 6ec53f89c..7543ac66b 100644
--- a/lisp/cli/packages.el
+++ b/lisp/cli/packages.el
@@ -825,10 +825,11 @@ However, in batch mode, print to stdout instead of stderr."
 (defadvice! doom-cli--straight-ignore-gitconfig-a (fn &rest args)
   "Prevent user and system git configuration from interfering with git calls."
   :around #'straight--process-call
-  (letenv! (("GIT_CONFIG" nil)
-            ("GIT_CONFIG_NOSYSTEM" "1")
-            ("GIT_CONFIG_GLOBAL" (or (getenv "DOOMGITCONFIG")
-                                     "/dev/null")))
+  (with-environment-variables
+      (("GIT_CONFIG" nil)
+       ("GIT_CONFIG_NOSYSTEM" "1")
+       ("GIT_CONFIG_GLOBAL" (or (getenv "DOOMGITCONFIG")
+                                "/dev/null")))
     (apply fn args)))
 
 ;; If the repo failed to clone correctly (usually due to a connection failure),
diff --git a/lisp/doom-lib.el b/lisp/doom-lib.el
index 474b64333..2c6640517 100644
--- a/lisp/doom-lib.el
+++ b/lisp/doom-lib.el
@@ -389,8 +389,7 @@ TRIGGER-HOOK is a list of quoted hooks and/or sharp-quoted functions."
   (let (file-name-handler-alist)
     (file-name-directory (macroexpand '(file!)))))
 
-;; REVIEW Should I deprecate this? The macro's name is so long...
-(defalias 'letenv! 'with-environment-variables)
+(define-obsolete-function-alias 'letenv! 'with-environment-variables "3.0.0")
 
 (put 'defun* 'lisp-indent-function 'defun)
 (defmacro letf! (bindings &rest body)
diff --git a/lisp/doom-straight.el b/lisp/doom-straight.el
index 64593c990..1ae7776bd 100644
--- a/lisp/doom-straight.el
+++ b/lisp/doom-straight.el
@@ -249,10 +249,11 @@ However, in batch mode, print to stdout instead of stderr."
 (defadvice! doom-straight--ignore-gitconfig-a (fn &rest args)
   "Prevent user and system git configuration from interfering with git calls."
   :around #'straight--process-call
-  (letenv! (("GIT_CONFIG" nil)
-            ("GIT_CONFIG_NOSYSTEM" "1")
-            ("GIT_CONFIG_GLOBAL" (or (getenv "DOOMGITCONFIG")
-                                     "/dev/null")))
+  (with-environment-variables
+      (("GIT_CONFIG" nil)
+       ("GIT_CONFIG_NOSYSTEM" "1")
+       ("GIT_CONFIG_GLOBAL" (or (getenv "DOOMGITCONFIG")
+                                "/dev/null")))
     (apply fn args)))
 
 ;; If the repo failed to clone correctly (usually due to a connection failure),
diff --git a/lisp/lib/config.el b/lisp/lib/config.el
index f3d7893bc..9771e8225 100644
--- a/lisp/lib/config.el
+++ b/lisp/lib/config.el
@@ -38,12 +38,13 @@
        (setq doom-bin "doom.ps1"))
      ;; Ensure the bin/doom operates with the same environment as this
      ;; running session.
-     (letenv! (("PATH" (string-join exec-path path-separator))
-               ("EMACS" (doom-path invocation-directory invocation-name))
-               ("EMACSDIR" doom-emacs-dir)
-               ("DOOMDIR" doom-user-dir)
-               ("DOOMLOCALDIR" doom-local-dir)
-               ("DEBUG" (if doom-debug-mode (number-to-string doom-log-level) "")))
+     (with-environment-variables
+         (("PATH" (string-join exec-path path-separator))
+          ("EMACS" (doom-path invocation-directory invocation-name))
+          ("EMACSDIR" doom-emacs-dir)
+          ("DOOMDIR" doom-user-dir)
+          ("DOOMLOCALDIR" doom-local-dir)
+          ("DEBUG" (if doom-debug-mode (number-to-string doom-log-level) "")))
        (with-current-buffer
            (compile (format ,command (expand-file-name doom-bin doom-bin-dir)) t)
          (let ((w (get-buffer-window (current-buffer))))
diff --git a/lisp/lib/packages.el b/lisp/lib/packages.el
index 6e0dfc282..b088431d6 100644
--- a/lisp/lib/packages.el
+++ b/lisp/lib/packages.el
@@ -58,10 +58,11 @@ package's name as a symbol, and whose CDR is the plist supplied to its
 ;;; Package management API
 
 (defun doom--ensure-straight (recipe pin)
-  (letenv! (("GIT_CONFIG" nil)
-            ("GIT_CONFIG_NOSYSTEM" "1")
-            ("GIT_CONFIG_GLOBAL" (or (getenv "DOOMGITCONFIG")
-                                     "/dev/null")))
+  (with-environment-variables
+      (("GIT_CONFIG" nil)
+       ("GIT_CONFIG_NOSYSTEM" "1")
+       ("GIT_CONFIG_GLOBAL" (or (getenv "DOOMGITCONFIG")
+                                "/dev/null")))
     (let ((repo-dir (doom-path straight-base-dir "straight/repos/straight.el"))
           (repo-url (concat "http" (if gnutls-verify-error "s")
                             "://github.com/"
diff --git a/lisp/lib/sandbox.el b/lisp/lib/sandbox.el
index f13516946..6a7ded7f9 100644
--- a/lisp/lib/sandbox.el
+++ b/lisp/lib/sandbox.el
@@ -49,9 +49,10 @@
 
 (defun doom--sandbox-run (&optional mode)
   "TODO"
-  (letenv! (("DOOMDIR" (if (eq mode 'vanilla-doom+)
-                           (expand-file-name "___does_not_exist___" temporary-file-directory)
-                         doom-user-dir)))
+  (with-environment-variables
+      (("DOOMDIR" (if (eq mode 'vanilla-doom+)
+                      (expand-file-name "___does_not_exist___" temporary-file-directory)
+                    doom-user-dir)))
     (doom--sandbox-launch
      (unless (memq mode '(doom vanilla-doom+)) '("-Q"))
      (let ((forms