diff --git a/ports/stm32f4/mpconfigport.mk b/ports/stm32f4/mpconfigport.mk
index 0dd4862ec5..93b22dc6af 100644
--- a/ports/stm32f4/mpconfigport.mk
+++ b/ports/stm32f4/mpconfigport.mk
@@ -20,10 +20,7 @@ CIRCUITPY_DIGITALIO = 1
 CIRCUITPY_ANALOGIO = 1
 CIRCUITPY_MICROCONTROLLER = 1
 CIRCUITPY_BUSIO = 1
-CIRCUITPY_TIME = 1
 CIRCUITPY_OS = 1
-CIRCUITPY_STRUCT = 1
-CIRCUITPY_MATH = 1
 
 #ifeq ($(MCU_SUB_VARIANT), stm32f412zx)
 #endif
diff --git a/py/circuitpy_mpconfig.mk b/py/circuitpy_mpconfig.mk
index c5756f4880..ac79d32d04 100644
--- a/py/circuitpy_mpconfig.mk
+++ b/py/circuitpy_mpconfig.mk
@@ -52,6 +52,11 @@ ifndef CIRCUITPY_DEFAULT_BUILD
   endif
 endif
 
+# Some features have no unique HAL component, and thus there's never
+# a reason to not include them. 
+ifndef CIRCUITPY_ALWAYS_BUILD
+  CIRCUITPY_ALWAYS_BUILD = 1
+endif
 
 
 # All builtin modules are listed below, with default values (0 for off, 1 for on)
@@ -151,7 +156,7 @@ endif
 CFLAGS += -DCIRCUITPY_I2CSLAVE=$(CIRCUITPY_I2CSLAVE)
 
 ifndef CIRCUITPY_MATH
-CIRCUITPY_MATH = $(CIRCUITPY_DEFAULT_BUILD)
+CIRCUITPY_MATH = $(CIRCUITPY_ALWAYS_BUILD)
 endif
 CFLAGS += -DCIRCUITPY_MATH=$(CIRCUITPY_MATH)
 
@@ -232,17 +237,17 @@ endif
 CFLAGS += -DCIRCUITPY_STORAGE=$(CIRCUITPY_STORAGE)
 
 ifndef CIRCUITPY_STRUCT
-CIRCUITPY_STRUCT = $(CIRCUITPY_DEFAULT_BUILD)
+CIRCUITPY_STRUCT = $(CIRCUITPY_ALWAYS_BUILD)
 endif
 CFLAGS += -DCIRCUITPY_STRUCT=$(CIRCUITPY_STRUCT)
 
 ifndef CIRCUITPY_SUPERVISOR
-CIRCUITPY_SUPERVISOR = $(CIRCUITPY_DEFAULT_BUILD)
+CIRCUITPY_SUPERVISOR = $(CIRCUITPY_ALWAYS_BUILD)
 endif
 CFLAGS += -DCIRCUITPY_SUPERVISOR=$(CIRCUITPY_SUPERVISOR)
 
 ifndef CIRCUITPY_TIME
-CIRCUITPY_TIME = $(CIRCUITPY_DEFAULT_BUILD)
+CIRCUITPY_TIME = $(CIRCUITPY_ALWAYS_BUILD)
 endif
 CFLAGS += -DCIRCUITPY_TIME=$(CIRCUITPY_TIME)