diff --git a/gnu/packages/bioinformatics.scm b/gnu/packages/bioinformatics.scm
index cbc018a360..0718b5e31c 100644
--- a/gnu/packages/bioinformatics.scm
+++ b/gnu/packages/bioinformatics.scm
@@ -21,6 +21,7 @@
 ;;; Copyright © 2020 Bonface Munyoki Kilyungi <bonfacemunyoki@gmail.com>
 ;;; Copyright © 2021 Tim Howes <timhowes@lavabit.com>
 ;;; Copyright © 2021 Hong Li <hli@mdc-berlin.de>
+;;; Copyright © 2021 Felix Gruber <felgru@posteo.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -7788,7 +7789,7 @@ (define-public shorah
                            ,(version-major+minor
                              (package-version python))
                            "/site-packages"))
-                    (pythonpath (getenv "PYTHONPATH"))
+                    (pythonpath (getenv "GUIX_PYTHONPATH"))
                     (script (string-append out "/bin/shorah")))
                (chmod script #o555)
                (wrap-program script `("PYTHONPATH" ":" prefix (,site ,pythonpath))))))
diff --git a/gnu/packages/debug.scm b/gnu/packages/debug.scm
index f4ef2fd5e1..6507c82fcc 100644
--- a/gnu/packages/debug.scm
+++ b/gnu/packages/debug.scm
@@ -7,6 +7,7 @@
 ;;; Copyright © 2020 Vincent Legoll <vincent.legoll@gmail.com>
 ;;; Copyright © 2020 Morgan Smith <Morgan.J.Smith@outlook.com>
 ;;; Copyright © 2020 Maxim Cournoyer <maxim.cournoyer@gmail.com>
+;;; Copyright © 2021 Felix Gruber <felgru@posteo.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -213,7 +214,7 @@ (define-public c-vise
          (add-after 'install 'wrap
            (lambda* (#:key outputs #:allow-other-keys)
              (let ((out (assoc-ref outputs "out"))
-                   (python-path (getenv "PYTHONPATH")))
+                   (python-path (getenv "GUIX_PYTHONPATH")))
                (wrap-program (string-append out "/bin/cvise")
                  `("PYTHONPATH" ":" prefix (,python-path)))
                #t))))))
diff --git a/gnu/packages/gnome.scm b/gnu/packages/gnome.scm
index e0e9c47458..e9e15460ab 100644
--- a/gnu/packages/gnome.scm
+++ b/gnu/packages/gnome.scm
@@ -61,6 +61,7 @@
 ;;; Copyright © 2021 Trevor Hass <thass@okstate.edu>
 ;;; Copyright © 2021 Solene Rapenne <solene@perso.pw>
 ;;; Copyright © 2021 Guillaume Le Vaillant <glv@posteo.net>
+;;; Copyright © 2021 Felix Gruber <felgru@posteo.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -4205,7 +4206,7 @@ (define-public drawing
                                            (package-version python))
                                          "/site-packages")))
                (wrap-program prog
-                 `("PYTHONPATH" = (,(getenv "PYTHONPATH") ,pylib))
+                 `("PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH") ,pylib))
                  `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH"))))
                #t))))))
     (native-inputs
@@ -11582,7 +11583,7 @@ (define-public apostrophe
                                            (package-version python))
                                          "/site-packages")))
                (wrap-program prog
-                 `("PYTHONPATH" = (,(getenv "PYTHONPATH") ,pylib))
+                 `("PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH") ,pylib))
                  `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH")))
                  `("PATH" prefix (,(dirname
                                     (search-input-file inputs
@@ -12218,7 +12219,7 @@ (define-public ocrfeeder
                                           (package-version python))
                                         "/site-packages")))
               (wrap-program prog
-                `("PYTHONPATH" = (,(getenv "PYTHONPATH") ,pylib))
+                `("PYTHONPATH" = (,(getenv "GUIX_PYTHONPATH") ,pylib))
                 `("GI_TYPELIB_PATH" = (,(getenv "GI_TYPELIB_PATH"))))
               #t))))))
     (native-inputs
diff --git a/gnu/packages/music.scm b/gnu/packages/music.scm
index 2c43f70aff..178f23c821 100644
--- a/gnu/packages/music.scm
+++ b/gnu/packages/music.scm
@@ -6886,7 +6886,7 @@ (define-public a2jmidid
                (substitute* (string-append bin "a2j")
                  (("a2j_control") (string-append bin "a2j_control")))
                (wrap-program (string-append bin "a2j_control")
-                `("PYTHONPATH" prefix (,(getenv "PYTHONPATH"))))
+                `("PYTHONPATH" prefix (,(getenv "GUIX_PYTHONPATH"))))
                #t))))))
     (build-system meson-build-system)
     (inputs
diff --git a/gnu/packages/syndication.scm b/gnu/packages/syndication.scm
index 215e8e32cb..a06fa4404e 100644
--- a/gnu/packages/syndication.scm
+++ b/gnu/packages/syndication.scm
@@ -2,6 +2,7 @@
 ;;; Copyright © 2016, 2017, 2019, 2020, 2021 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2018, 2019 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;; Copyright © 2020 Vinicius Monego <monego@posteo.net>
+;;; Copyright © 2021 Felix Gruber <felgru@posteo.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -605,7 +606,7 @@ (define-public gfeeds
            (lambda* (#:key outputs #:allow-other-keys)
              (wrap-program (string-append
                             (assoc-ref outputs "out") "/bin/gfeeds")
-               `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH")))
+               `("PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH")))
                `("GI_TYPELIB_PATH" ":" prefix (,(getenv "GI_TYPELIB_PATH")))
                `("XDG_DATA_DIRS" ":" prefix (,(getenv "XDG_DATA_DIRS"))))
              #t)))))
diff --git a/gnu/packages/xdisorg.scm b/gnu/packages/xdisorg.scm
index 8502cb67eb..6f05b8056b 100644
--- a/gnu/packages/xdisorg.scm
+++ b/gnu/packages/xdisorg.scm
@@ -51,6 +51,7 @@
 ;;; Copyright © 2021 Niklas Eklund <niklas.eklund@posteo.net>
 ;;; Copyright © 2021 Nikita Domnitskii <nikita@domnitskii.me>
 ;;; Copyright © 2021 ikasero <ahmed@ikasero.com>
+;;; Copyright © 2021 Felix Gruber <felgru@posteo.net>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -1557,7 +1558,7 @@ (define-public gammastep
              ;; to Python libraries.
              (wrap-program (string-append (assoc-ref outputs "out")
                                           "/bin/gammastep-indicator")
-               `("PYTHONPATH" ":" prefix (,(getenv "PYTHONPATH")))
+               `("PYTHONPATH" ":" prefix (,(getenv "GUIX_PYTHONPATH")))
                `("GI_TYPELIB_PATH" ":" prefix
                  (,(getenv "GI_TYPELIB_PATH")))))))))
     (native-inputs