diff --git a/tests/toranj/openthread-core-toranj-config-posix.h b/tests/toranj/openthread-core-toranj-config-posix.h
index f7b968352..48ad85f0e 100644
--- a/tests/toranj/openthread-core-toranj-config-posix.h
+++ b/tests/toranj/openthread-core-toranj-config-posix.h
@@ -40,8 +40,6 @@
 
 #define OPENTHREAD_CONFIG_MULTICAST_DNS_ENABLE 1
 
-#define OPENTHREAD_CONFIG_MULTICAST_DNS_ENABLE 1
-
 #define OPENTHREAD_CONFIG_MULTICAST_DNS_PUBLIC_API_ENABLE 1
 
 #define OPENTHREAD_CONFIG_PLATFORM_DNSSD_ENABLE 0