diff --git a/rtc.cpp b/rtc.cpp
index a64a5b2..8ebef4d 100644
--- a/rtc.cpp
+++ b/rtc.cpp
@@ -271,7 +271,7 @@ void rtc_run_clock(bool run)
   else
     b |= _BV(CH_BIT); // set bit
     
-    rtc_write_byte(b, 0x0);
+  rtc_write_byte(b, 0x0);
 }
 
 // DS1307 only
diff --git a/twi-lowlevel.cpp b/twi-lowlevel.cpp
index c50f3b5..73268b4 100644
--- a/twi-lowlevel.cpp
+++ b/twi-lowlevel.cpp
@@ -369,6 +369,7 @@ SIGNAL(TWI_vect)
     case TW_MR_DATA_ACK: // data received, ack sent
       // put byte into buffer
       twi_masterBuffer[twi_masterBufferIndex++] = TWDR;
+	  [[fallthrough]];
     case TW_MR_SLA_ACK:  // address sent, ack received
       // ack if more bytes are expected, otherwise nack
       if(twi_masterBufferIndex < twi_masterBufferLength){
@@ -380,6 +381,7 @@ SIGNAL(TWI_vect)
     case TW_MR_DATA_NACK: // data received, nack sent
       // put final byte into buffer
       twi_masterBuffer[twi_masterBufferIndex++] = TWDR;
+	  [[fallthrough]];
     case TW_MR_SLA_NACK: // address sent, nack received
       twi_stop();
       break;
@@ -446,6 +448,7 @@ SIGNAL(TWI_vect)
         twi_txBuffer[0] = 0x00;
       }
       // transmit first byte from buffer, fall
+	  [[fallthrough]];
     case TW_ST_DATA_ACK: // byte sent, ack returned
       // copy data to output register
       TWDR = twi_txBuffer[twi_txBufferIndex++];