diff --git a/py/persistentcode.h b/py/persistentcode.h
index 2074c64fe..67c5f3463 100644
--- a/py/persistentcode.h
+++ b/py/persistentcode.h
@@ -31,7 +31,7 @@
 #include "py/emitglue.h"
 
 // The current version of .mpy files
-#define MPY_VERSION 4
+#define MPY_VERSION 5
 
 enum {
     MP_NATIVE_ARCH_NONE = 0,
diff --git a/tests/import/mpy_native.py b/tests/import/mpy_native.py
index f1d862d29..25fceb9bb 100644
--- a/tests/import/mpy_native.py
+++ b/tests/import/mpy_native.py
@@ -50,11 +50,11 @@ class UserFS:
 # these are the test .mpy files
 user_files = {
     # bad architecture
-    '/mod0.mpy': b'M\x04\xff\x00\x10',
+    '/mod0.mpy': b'M\x05\xff\x00\x10',
 
     # test loading of viper and asm
     '/mod1.mpy': (
-        b'M\x04\x0b\x1f\x20' # header
+        b'M\x05\x0b\x1f\x20' # header
 
         b'\x38' # n bytes, bytecode
             b'\x01\x00\x00\x00\x00\x00\x05\x00\x00\x00\x00\xff' # prelude
diff --git a/tools/mpy-tool.py b/tools/mpy-tool.py
index c6f90e4f8..4f8e965d7 100755
--- a/tools/mpy-tool.py
+++ b/tools/mpy-tool.py
@@ -57,7 +57,7 @@ class FreezeError(Exception):
         return 'error while freezing %s: %s' % (self.rawcode.source_file, self.msg)
 
 class Config:
-    MPY_VERSION = 4
+    MPY_VERSION = 5
     MICROPY_LONGINT_IMPL_NONE = 0
     MICROPY_LONGINT_IMPL_LONGLONG = 1
     MICROPY_LONGINT_IMPL_MPZ = 2