diff --git a/Marlin/src/gcode/queue.cpp b/Marlin/src/gcode/queue.cpp
index a764d80ec..0f4169a2c 100644
--- a/Marlin/src/gcode/queue.cpp
+++ b/Marlin/src/gcode/queue.cpp
@@ -288,6 +288,7 @@ inline bool any_serial_data_available() {
   LOOP_L_N(p, NUM_SERIAL)
     if (serial_data_available(p))
       return true;
+  return false;
 }
 
 inline int read_serial(const serial_index_t index) { return SERIAL_IMPL.read(index); }
diff --git a/Marlin/src/gcode/sd/M28_M29.cpp b/Marlin/src/gcode/sd/M28_M29.cpp
index f34edb6f7..373938d99 100644
--- a/Marlin/src/gcode/sd/M28_M29.cpp
+++ b/Marlin/src/gcode/sd/M28_M29.cpp
@@ -49,7 +49,7 @@ void GcodeSuite::M28() {
     // Binary transfer mode
     if ((card.flag.binary_mode = binary_mode)) {
       SERIAL_ECHO_MSG("Switching to Binary Protocol");
-      TERN_(HAS_MULTI_SERIAL, card.transfer_port_index = queue.ring_buffer.command_port());
+      TERN_(HAS_MULTI_SERIAL, card.transfer_port_index = queue.ring_buffer.command_port().index);
     }
     else
       card.openFileWrite(p);