diff --git a/pymc-repeater.service b/pymc-repeater.service
index 8c07d40..774d707 100644
--- a/pymc-repeater.service
+++ b/pymc-repeater.service
@@ -31,6 +31,7 @@ SyslogIdentifier=pymc-repeater
 # Security (relaxed for proper operation)
 NoNewPrivileges=true
 ReadWritePaths=/var/log/pymc_repeater /var/lib/pymc_repeater /etc/pymc_repeater
+SupplementaryGroups=plugdev dialout gpio i2c spi
 
 [Install]
 WantedBy=multi-user.target