diff --git a/boot/espressif/os.c b/boot/espressif/os.c
index 9b9d55b..2a2e9ca 100644
--- a/boot/espressif/os.c
+++ b/boot/espressif/os.c
@@ -9,7 +9,7 @@
 #include <mbedtls/platform.h>
 #include <mbedtls/memory_buffer_alloc.h>
 
-#define CRYPTO_HEAP_SIZE 16384
+#define CRYPTO_HEAP_SIZE 8192
 
 static unsigned char memory_buf[CRYPTO_HEAP_SIZE];