diff --git a/Makefile b/Makefile
index 9a700d1..9e99e5a 100644
--- a/Makefile
+++ b/Makefile
@@ -83,8 +83,12 @@ EMULATOR=0
 endif
 
 ifeq ("$(EMULATOR_SDK)","")
+ifeq ("$(NANO_MODEL)","nanox")
+EMULATOR_SDK=1.2
+else
 EMULATOR_SDK=2.0
 endif
+endif
 
 ifeq ("$(NO_EMULATOR_TESTS)","")
 EMULATOR_TESTS=1
@@ -141,7 +145,7 @@ DEFINES   += UNUSED\(x\)=\(void\)x
 DEFINES   += APPVERSION=\"$(APPVERSION)\"
 
 ifeq ($(TARGET_NAME),TARGET_NANOX)
-DEFINES   	  += IO_SEPROXYHAL_BUFFER_SIZE_B=300
+DEFINES       += BUILD_NANOX IO_SEPROXYHAL_BUFFER_SIZE_B=300
 DEFINES       += HAVE_BLE BLE_COMMAND_TIMEOUT_MS=2000
 DEFINES       += HAVE_BLE_APDU # basic ledger apdu transport over BLE
 
diff --git a/src/crypto.c b/src/crypto.c
index 583a209..1d5fdbc 100644
--- a/src/crypto.c
+++ b/src/crypto.c
@@ -11,9 +11,11 @@
 //         GROUP_ORDER   = 28948022309329048855892746252171976963363056481941647379679742748393362948097 (Fq, 0x94)
 //         FIELD_MODULUS = 28948022309329048855892746252171976963363056481941560715954676764349967630337 (Fp, 0x4c)
 
+#ifndef BUILD_NANOX
 #include <lcx_sha256.h>
 #include <lcx_blake2.h>
 #include <lcx_math.h>
+#endif
 
 #include "crypto.h"
 #include "poseidon.h"
diff --git a/tests/Makefile b/tests/Makefile
index 5770e2f..f7bfae6 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -3,23 +3,33 @@ EMULATOR=1
 else
 EMULATOR=0
 endif
+
 ifeq ("$(EMULATOR_SDK)","")
+ifeq ("$(NANO_MODEL)","nanox")
+EMULATOR_SDK=1.2
+else
 EMULATOR_SDK=2.0
 endif
+endif
+
 ifeq ("$(NO_EMULATOR_TESTS)","")
 EMULATOR_TESTS=1
 else
 EMULATOR_TESTS=0
 endif
+
 ifeq ("$(NANO_MODEL)","nanos")
 EMULATOR_MODEL=nanos
 endif
+
 ifeq ("$(NANO_MODEL)","nanox")
 EMULATOR_MODEL=nanox
 endif
+
 ifeq ("$(EMULATOR_MODEL)","")
 $(error Unknown NANO_MODEL '$(NANO_MODEL)')
 endif
+
 ifeq ("$(EMULATOR_MODEL)","")
 $(error Environment variable EMULATOR_MODEL is not set (source ./prepare-devenv.sh))
 endif