diff --git a/ports/atmel-samd/mpconfigport.mk b/ports/atmel-samd/mpconfigport.mk
index ee68c079ad..92d47b186a 100644
--- a/ports/atmel-samd/mpconfigport.mk
+++ b/ports/atmel-samd/mpconfigport.mk
@@ -64,22 +64,12 @@ ifndef CIRCUITPY_SAMD
 CIRCUITPY_SAMD = 1
 endif
 
-ifndef CIRCUITPY_ULAB
-ifneq ($(CIRCUITPY_FULL_BUILD),0)
-CIRCUITPY_ULAB = 1
-endif
-endif
-
 ifndef CIRCUITPY_RGBMATRIX
-ifneq ($(CIRCUITPY_FULL_BUILD),0)
-CIRCUITPY_RGBMATRIX = 1
-endif
+CIRCUITPY_RGBMATRIX = $(CIRCUITPY_FULL_BUILD)
 endif
 
 ifndef CIRCUITPY_FRAMEBUFFERIO
-ifneq ($(CIRCUITPY_FULL_BUILD),0)
-CIRCUITPY_FRAMEBUFFERIO = 1
-endif
+CIRCUITPY_FRAMEBUFFERIO = $(CIRCUITPY_FULL_BUILD)
 endif
 
 endif # samd51
diff --git a/py/circuitpy_mpconfig.mk b/py/circuitpy_mpconfig.mk
index 9f0a1684a8..30ab720d70 100644
--- a/py/circuitpy_mpconfig.mk
+++ b/py/circuitpy_mpconfig.mk
@@ -319,6 +319,7 @@ CFLAGS += -DCIRCUITPY_SERIAL_UART=$(CIRCUITPY_SERIAL_UART)
 ifndef CIRCUITPY_ULAB
 CIRCUITPY_ULAB = $(CIRCUITPY_FULL_BUILD)
 endif
+CFLAGS += -DCIRCUITPY_ULAB=$(CIRCUITPY_ULAB)
 
 # Enabled micropython.native decorator (experimental)
 ifndef CIRCUITPY_ENABLE_MPY_NATIVE