diff --git a/core/core.el b/core/core.el
index 093efc1d3..1a5130f18 100644
--- a/core/core.el
+++ b/core/core.el
@@ -417,12 +417,13 @@ in interactive sessions, nil otherwise (but logs a warning)."
   (if (not (file-readable-p file))
       (unless noerror
         (signal 'file-error (list "Couldn't read envvar file" file)))
-    (let (environment)
+    (let (envvars environment)
       (with-temp-buffer
         (save-excursion
           (insert "\n")
           (insert-file-contents file))
         (while (re-search-forward "\n *\\([^#= \n]*\\)=" nil t)
+          (push (match-string 1) envvars)
           (push (buffer-substring
                  (match-beginning 1)
                  (1- (or (save-excursion
@@ -431,13 +432,19 @@ in interactive sessions, nil otherwise (but logs a warning)."
                          (point-max))))
                 environment)))
       (when environment
-        (setq-default
-         process-environment (nreverse environment)
-         exec-path (append (parse-colon-path (getenv "PATH"))
-                           (list exec-directory))
-         shell-file-name (or (getenv "SHELL")
-                             shell-file-name))
-        process-environment))))
+        (setq process-environment
+              (append (nreverse environment) process-environment)
+              exec-path
+              (if (member "PATH" envvars)
+                  (append (parse-colon-path (getenv "PATH"))
+                          (list exec-directory))
+                exec-path)
+              shell-file-name
+              (if (member "SHELL" envvars)
+                  (setq shell-file-name
+                        (or (getenv "SHELL") shell-file-name))
+                shell-file-name))
+        envvars))))
 
 (defun doom-initialize (&optional force-p)
   "Bootstrap Doom, if it hasn't already (or if FORCE-P is non-nil).
diff --git a/core/test/test-core.el b/core/test/test-core.el
index 0207390b4..6b9305c13 100644
--- a/core/test/test-core.el
+++ b/core/test/test-core.el
@@ -117,7 +117,7 @@
 
     (it "returns the new value for `process-environment'"
       (expect (doom-load-envvars-file doom-env-file)
-              :to-equal '("A=1" "B=2" "C=3")))
+              :to-have-same-items-as '("A" "B" "C")))
 
     (it "alters environment variables"
       (dolist (key '("A" "B" "C"))