diff --git a/ports/nrf/mpconfigdevice_nrf52840.h b/ports/nrf/mpconfigdevice_nrf52840.h
index fa9258f2ac..581c52ea81 100644
--- a/ports/nrf/mpconfigdevice_nrf52840.h
+++ b/ports/nrf/mpconfigdevice_nrf52840.h
@@ -34,6 +34,16 @@
 #define MICROPY_VFS                        (1)
 #endif
 
+// Board overridable emitter configuration.
+
+#ifndef MICROPY_EMIT_THUMB
+#define MICROPY_EMIT_THUMB          (1)
+#endif
+
+#ifndef MICROPY_EMIT_INLINE_THUMB
+#define MICROPY_EMIT_INLINE_THUMB   (1)
+#endif
+
 // Board overridable feature configuration.
 
 #ifndef MICROPY_ENABLE_SOURCE_LINE
diff --git a/ports/nrf/mpconfigdevice_nrf9160.h b/ports/nrf/mpconfigdevice_nrf9160.h
index fa9258f2ac..581c52ea81 100644
--- a/ports/nrf/mpconfigdevice_nrf9160.h
+++ b/ports/nrf/mpconfigdevice_nrf9160.h
@@ -34,6 +34,16 @@
 #define MICROPY_VFS                        (1)
 #endif
 
+// Board overridable emitter configuration.
+
+#ifndef MICROPY_EMIT_THUMB
+#define MICROPY_EMIT_THUMB          (1)
+#endif
+
+#ifndef MICROPY_EMIT_INLINE_THUMB
+#define MICROPY_EMIT_INLINE_THUMB   (1)
+#endif
+
 // Board overridable feature configuration.
 
 #ifndef MICROPY_ENABLE_SOURCE_LINE
diff --git a/ports/nrf/mpconfigport.h b/ports/nrf/mpconfigport.h
index af77ef69ca..8a622d811c 100644
--- a/ports/nrf/mpconfigport.h
+++ b/ports/nrf/mpconfigport.h
@@ -43,7 +43,7 @@
 #define MICROPY_VFS                 (0)
 #endif
 #define MICROPY_ALLOC_PATH_MAX      (512)
-#define MICROPY_PERSISTENT_CODE_LOAD (0)
+#define MICROPY_PERSISTENT_CODE_LOAD (1)
 #define MICROPY_COMP_MODULE_CONST   (0)
 #define MICROPY_COMP_TRIPLE_TUPLE_ASSIGN (0)
 #define MICROPY_READER_VFS          (MICROPY_VFS)
@@ -103,7 +103,7 @@
 #define MICROPY_CAN_OVERRIDE_BUILTINS (1)
 #define MICROPY_USE_INTERNAL_ERRNO  (1)
 #define MICROPY_PY_FUNCTION_ATTRS   (1)
-#define MICROPY_PY_BUILTINS_STR_UNICODE (0)
+#define MICROPY_PY_BUILTINS_STR_UNICODE (1)
 #define MICROPY_PY_BUILTINS_STR_CENTER (0)
 #define MICROPY_PY_BUILTINS_STR_PARTITION (0)
 #define MICROPY_PY_BUILTINS_STR_SPLITLINES (0)