diff --git a/py/modbuiltins.c b/py/modbuiltins.c
index 594f385f4c968f7fbf66424f55bbecd1ed813038..c7323afaad58a2f6de16bba15cdb6206452f4b45 100644
--- a/py/modbuiltins.c
+++ b/py/modbuiltins.c
@@ -683,6 +683,9 @@ STATIC const mp_map_elem_t mp_module_builtins_globals_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_SyntaxError), (mp_obj_t)&mp_type_SyntaxError },
     { MP_OBJ_NEW_QSTR(MP_QSTR_SystemExit), (mp_obj_t)&mp_type_SystemExit },
     { MP_OBJ_NEW_QSTR(MP_QSTR_TypeError), (mp_obj_t)&mp_type_TypeError },
+    #if MICROPY_PY_BUILTINS_STR_UNICODE
+    { MP_OBJ_NEW_QSTR(MP_QSTR_UnicodeError), (mp_obj_t)&mp_type_UnicodeError },
+    #endif
     { MP_OBJ_NEW_QSTR(MP_QSTR_ValueError), (mp_obj_t)&mp_type_ValueError },
     { MP_OBJ_NEW_QSTR(MP_QSTR_ZeroDivisionError), (mp_obj_t)&mp_type_ZeroDivisionError },
     // Somehow CPython managed to have OverflowError not inherit from ValueError ;-/
diff --git a/py/obj.h b/py/obj.h
index 3a9a6431c2123878813e6290de1d7a4e2ee30ff6..db42e795a2bb82042defea63ebd0ecf4c5224dcf 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -369,6 +369,7 @@ extern const mp_obj_type_t mp_type_StopIteration;
 extern const mp_obj_type_t mp_type_SyntaxError;
 extern const mp_obj_type_t mp_type_SystemExit;
 extern const mp_obj_type_t mp_type_TypeError;
+extern const mp_obj_type_t mp_type_UnicodeError;
 extern const mp_obj_type_t mp_type_ValueError;
 extern const mp_obj_type_t mp_type_ZeroDivisionError;
 
diff --git a/py/objexcept.c b/py/objexcept.c
index 858804d0b7283d0a233ccd7ce70eb106d0b26aac..824c9b0ad74050fe438edbc6c9109a1ae8dccfc9 100644
--- a/py/objexcept.c
+++ b/py/objexcept.c
@@ -249,7 +249,11 @@ MP_DEFINE_EXCEPTION(Exception, BaseException)
   //MP_DEFINE_EXCEPTION(SystemError, Exception)
   MP_DEFINE_EXCEPTION(TypeError, Exception)
   MP_DEFINE_EXCEPTION(ValueError, Exception)
-    //TODO: Implement UnicodeErrors which take arguments
+#if MICROPY_PY_BUILTINS_STR_UNICODE
+    MP_DEFINE_EXCEPTION_BASE(ValueError)
+    MP_DEFINE_EXCEPTION(UnicodeError, ValueError)
+    //TODO: Implement more UnicodeError subclasses which take arguments
+#endif
   /*
   MP_DEFINE_EXCEPTION(Warning, Exception)
     MP_DEFINE_EXCEPTION_BASE(Warning)
diff --git a/py/qstrdefs.h b/py/qstrdefs.h
index 77514f521bb419a33717a06e40a67733fc16791f..88c0d5a3efdc32a35273d6ba132842e20542c25f 100644
--- a/py/qstrdefs.h
+++ b/py/qstrdefs.h
@@ -137,6 +137,9 @@ Q(TypeError)
 Q(UnboundLocalError)
 Q(ValueError)
 Q(ZeroDivisionError)
+#if MICROPY_PY_BUILTINS_STR_UNICODE
+Q(UnicodeError)
+#endif
 
 Q(None)
 Q(False)