diff --git a/esp8266/main.c b/esp8266/main.c
index 908a2c6..4fc7757 100644
--- a/esp8266/main.c
+++ b/esp8266/main.c
@@ -38,7 +38,7 @@
 #include "gccollect.h"
 #include "user_interface.h"
 
-STATIC char heap[16384];
+STATIC char heap[15360];
 
 STATIC void mp_reset(void) {
     mp_stack_set_top((void*)0x40000000);