diff --git a/src/relay_chn_ctl_single.c b/src/relay_chn_ctl_single.c
index dcb3ac7..753174d 100644
--- a/src/relay_chn_ctl_single.c
+++ b/src/relay_chn_ctl_single.c
@@ -15,7 +15,7 @@
 #include "relay_chn_nvs.h"
 #endif
 
-static const char *TAG = "RELAY_CHN_CTL";
+static const char *TAG __attribute__((unused)) = "RELAY_CHN_CTL";
 
 static relay_chn_ctl_t s_chn_ctl;