diff --git a/src/eac.c b/src/eac.c
index 9492aac..1821516 100644
--- a/src/eac.c
+++ b/src/eac.c
@@ -21,6 +21,11 @@
 #include "mbedtls/cmac.h"
 #include "asn1.h"
 #include "apdu.h"
+#ifdef ENABLE_EMULATION
+#include "usb/emulation/emulation.h"
+#else
+#include "usb/usb.h"
+#endif
 
 static uint8_t sm_nonce[8];
 static uint8_t sm_kmac[16];
@@ -144,7 +149,7 @@ int sm_wrap() {
     if (sm_indicator == 0) {
         return PICOKEY_OK;
     }
-    uint8_t input[2048];
+    uint8_t input[USB_BUFFER_SIZE];
     size_t input_len = 0;
     memset(input, 0, sizeof(input));
     mbedtls_mpi ssc;
@@ -232,7 +237,7 @@ void sm_update_iv() {
 }
 
 int sm_verify() {
-    uint8_t input[2048];
+    uint8_t input[USB_BUFFER_SIZE];
     memset(input, 0, sizeof(input));
     uint16_t input_len = 0;
     int r = 0;
diff --git a/src/fs/flash.c b/src/fs/flash.c
index b5c8bf3..e71a985 100644
--- a/src/fs/flash.c
+++ b/src/fs/flash.c
@@ -22,7 +22,11 @@
 
 #if !defined(PICO_PLATFORM)
 #define XIP_BASE                0
-#define FLASH_SECTOR_SIZE       4096
+#ifdef ENABLE_EMULATION
+#define FLASH_SECTOR_SIZE       0x4000
+#else
+#define FLASH_SECTOR_SIZE       0x1000
+#endif
 #ifdef ESP_PLATFORM
 uint32_t FLASH_SIZE_BYTES = (1 * 1024 * 1024);
 #else
diff --git a/src/fs/low_flash.c b/src/fs/low_flash.c
index 3c72333..e2f7c6a 100644
--- a/src/fs/low_flash.c
+++ b/src/fs/low_flash.c
@@ -58,7 +58,11 @@
   #endif
   #include "queue.h"
  #endif
- #define FLASH_SECTOR_SIZE       4096
+ #ifdef ENABLE_EMULATION
+    #define FLASH_SECTOR_SIZE       0x4000
+ #else
+    #define FLASH_SECTOR_SIZE       0x1000
+ #endif
  #define XIP_BASE 0
  int fd_map = 0;
  uint8_t *map = NULL;
diff --git a/src/usb/emulation/emulation.h b/src/usb/emulation/emulation.h
index a926d81..75c90dc 100644
--- a/src/usb/emulation/emulation.h
+++ b/src/usb/emulation/emulation.h
@@ -24,7 +24,7 @@
 #include "board.h"
 #include <stdbool.h>
 
-#define USB_BUFFER_SIZE 2048
+#define USB_BUFFER_SIZE 4096
 extern int emul_init(char *host, uint16_t port);
 extern uint8_t emul_rx[USB_BUFFER_SIZE];
 extern uint16_t emul_rx_size, emul_tx_size;
diff --git a/src/usb/usb.h b/src/usb/usb.h
index 962709b..c34ee48 100644
--- a/src/usb/usb.h
+++ b/src/usb/usb.h
@@ -106,7 +106,9 @@ extern void driver_exec_finished_emul(uint8_t itf, uint16_t size_next);
 extern void driver_exec_finished_cont_emul(uint8_t itf, uint16_t size_next, uint16_t offset);
 #endif
 
+#ifndef USB_BUFFER_SIZE
 #define USB_BUFFER_SIZE         2048
+#endif
 
 PACK(
 typedef struct {