diff --git a/Marlin/src/lcd/HardwareSerial.cpp b/Marlin/src/lcd/HardwareSerial.cpp
index 8c54d805..2727125e 100755
--- a/Marlin/src/lcd/HardwareSerial.cpp
+++ b/Marlin/src/lcd/HardwareSerial.cpp
@@ -42,9 +42,9 @@
 // to which to write the next incoming character and tail is the index of the
 // location from which to read.
 #if (RAMEND < 1000)
-  #define SERIAL_BUFFER_SIZE 64
+  #define SERIAL_BUFFER_SIZE 16
 #else
-  #define SERIAL_BUFFER_SIZE 128
+  #define SERIAL_BUFFER_SIZE 64
 #endif
 
 struct ring_buffer