diff --git a/include/mbedtls/compat-1.3.h b/include/mbedtls/compat-1.3.h
index 600a0f1..213b691 100644
--- a/include/mbedtls/compat-1.3.h
+++ b/include/mbedtls/compat-1.3.h
@@ -1378,7 +1378,8 @@
 #define SSL_ANTI_REPLAY_ENABLED MBEDTLS_SSL_ANTI_REPLAY_ENABLED
 #define SSL_ARC4_DISABLED MBEDTLS_SSL_ARC4_DISABLED
 #define SSL_ARC4_ENABLED MBEDTLS_SSL_ARC4_ENABLED
-#define SSL_BUFFER_LEN MBEDTLS_SSL_BUFFER_LEN
+#define SSL_BUFFER_LEN ( ( ( MBEDTLS_SSL_IN_BUFFER_LEN ) < ( MBEDTLS_SSL_OUT_BUFFER_LEN ) ) \
+                         ? ( MBEDTLS_SSL_IN_BUFFER_LEN ) : ( MBEDTLS_SSL_OUT_BUFFER_LEN ) )
 #define SSL_CACHE_DEFAULT_MAX_ENTRIES MBEDTLS_SSL_CACHE_DEFAULT_MAX_ENTRIES
 #define SSL_CACHE_DEFAULT_TIMEOUT MBEDTLS_SSL_CACHE_DEFAULT_TIMEOUT
 #define SSL_CBC_RECORD_SPLITTING_DISABLED MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED