diff --git a/chconf.h b/chconf.h
index 08860ae..deb0f9e 100644
--- a/chconf.h
+++ b/chconf.h
@@ -529,7 +529,7 @@
 /**
  * ChibiOS/os/various/shell/shell_cmd.c
  */
-#define SHELL_CMD_EXIT_ENABLED TRUE
+#define SHELL_CMD_EXIT_ENABLED FALSE
 #define SHELL_CMD_INFO_ENABLED FALSE
 #define SHELL_CMD_ECHO_ENABLED FALSE
 #define SHELL_CMD_SYSTIME_ENABLED FALSE
diff --git a/nanovna.h b/nanovna.h
index 3c952b5..5b19e7b 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -502,7 +502,7 @@ extern volatile uint8_t redraw_request;
 #define RGBHEX(hex) ( (((hex)&0x001c00)<<3) | (((hex)&0x0000f8)<<5) | (((hex)&0xf80000)>>16) | (((hex)&0x00e000)>>13) )
 
 // Define size of screen buffer in pixels (one pixel 16bit size)
-#define SPI_BUFFER_SIZE             1024
+#define SPI_BUFFER_SIZE             (CELLWIDTH*CELLHEIGHT)
 
 #define LCD_WIDTH                   320
 #define LCD_HEIGHT                  240
diff --git a/sa_core.c b/sa_core.c
index 32e8612..42a6695 100644
--- a/sa_core.c
+++ b/sa_core.c
@@ -34,7 +34,7 @@ uint32_t maxFreq = 520000000;
 uint32_t measured_sweep_time = 0;
 
 //int setting.refer = -1;  // Off by default
-int const reffer_freq[] = {30000000, 15000000, 10000000, 4000000, 3000000, 2000000, 1000000};
+static const int reffer_freq[] = {30000000, 15000000, 10000000, 4000000, 3000000, 2000000, 1000000};
 
 int in_selftest = false;