diff --git a/mbsync/.mbsyncrc b/mbsync/.mbsyncrc
index a47483a..705f5f5 100644
--- a/mbsync/.mbsyncrc
+++ b/mbsync/.mbsyncrc
@@ -58,7 +58,7 @@ IMAPAccount ugent
 Host outlook.office365.com
 User amin.kasrouaouam@ugent.be
 AuthMechs XOAUTH2
-PassCmd "/home/coolneng/.local/share/scripts/mutt_oauth2.py /home/coolneng/.cache/tokenfile"
+PassCmd "nix-shell -p python3 --command 'python /home/coolneng/.local/share/scripts/mutt_oauth2.py /home/coolneng/.cache/tokenfile'"
 SSLType IMAPS
 CertificateFile /etc/ssl/certs/ca-certificates.crt
 
diff --git a/msmtp/.msmtprc b/msmtp/.msmtprc
index d145f87..cdadc8f 100644
--- a/msmtp/.msmtprc
+++ b/msmtp/.msmtprc
@@ -19,7 +19,7 @@ host smtp.office365.com
 port 587
 from amin.kasrouaouam@ugent.be
 user amin.kasrouaouam@ugent.be
-passwordeval "/home/coolneng/.local/share/scripts/mutt_oauth2.py /home/coolneng/.cache/tokenfile"
+passwordeval "nix-shell -p python3 --command 'python /home/coolneng/.local/share/scripts/mutt_oauth2.py /home/coolneng/.cache/tokenfile'"
 
 account disroot
 host disroot.org
diff --git a/neomutt/.config/neomutt/etc/sendmail b/neomutt/.config/neomutt/etc/sendmail
index c2a69de..d899f10 100755
--- a/neomutt/.config/neomutt/etc/sendmail
+++ b/neomutt/.config/neomutt/etc/sendmail
@@ -1,3 +1,3 @@
 #!/bin/sh
 
-nix-shell -p python39 --command "python ~/.local/bin/MIMEmbellish | msmtp -a $1 -t"
+nix-shell -p python3 --command "python ~/.local/bin/MIMEmbellish | msmtp -a $1 -t"