diff --git a/ports/bare-arm/README.md b/ports/bare-arm/README.md
index dfa5534d59..37e373e2b6 100644
--- a/ports/bare-arm/README.md
+++ b/ports/bare-arm/README.md
@@ -18,4 +18,4 @@ compiled and executed when the firmware starts.  They produce output on the
 system's stdout.
 
 The size of the firmware (the machine code that is programmed to the
-microcontroller's flash/ROM) is currently around 57900 bytes.
+microcontroller's flash/ROM) is currently around 56500 bytes.
diff --git a/ports/bare-arm/mpconfigport.h b/ports/bare-arm/mpconfigport.h
index 1a6466ccf4..65bb67f7b9 100644
--- a/ports/bare-arm/mpconfigport.h
+++ b/ports/bare-arm/mpconfigport.h
@@ -31,24 +31,11 @@
 // Use the minimal starting configuration (disables all optional features).
 #define MICROPY_CONFIG_ROM_LEVEL                (MICROPY_CONFIG_ROM_LEVEL_MINIMUM)
 
-// Memory allocation policy
-#define MICROPY_GC_ALLOC_THRESHOLD              (1)
-
 // Compiler configuration
 #define MICROPY_ENABLE_COMPILER                 (1)
-#define MICROPY_COMP_CONST_FOLDING              (1)
-#define MICROPY_COMP_CONST_LITERAL              (1)
 
 // Python internal features
 #define MICROPY_ERROR_REPORTING                 (MICROPY_ERROR_REPORTING_NONE)
-#define MICROPY_FULL_CHECKS                     (1)
-
-// Fine control over Python builtins, classes, modules, etc
-#define MICROPY_MULTIPLE_INHERITANCE            (1)
-#define MICROPY_PY_GENERATOR_PEND_THROW         (1)
-#define MICROPY_PY_BUILTINS_RANGE_ATTRS         (1)
-#define MICROPY_PY_BUILTINS_FILTER              (1)
-#define MICROPY_PY_BUILTINS_MIN_MAX             (1)
 
 // Type definitions for the specific machine