diff --git a/examples/platform/silabs/efr32/rs911x/hal/sl_si91x_ncp_utility.h b/examples/platform/silabs/efr32/rs911x/hal/sl_si91x_ncp_utility.h
index 0f0bcfbc919059..ea188720bed7b2 100644
--- a/examples/platform/silabs/efr32/rs911x/hal/sl_si91x_ncp_utility.h
+++ b/examples/platform/silabs/efr32/rs911x/hal/sl_si91x_ncp_utility.h
@@ -40,7 +40,6 @@
 #define USART_INITSYNC_BAUDRATE 12500000
 
 #if SL_SPICTRL_MUX
-extern SemaphoreHandle_t spi_sem_sync_hdl;
 sl_status_t spi_board_init(void);
 #endif // SL_SPICTRL_MUX