diff --git a/ports/nrf/Makefile b/ports/nrf/Makefile
index 8fa07ca450..2a9bf8eb79 100644
--- a/ports/nrf/Makefile
+++ b/ports/nrf/Makefile
@@ -238,7 +238,7 @@ OBJ += $(BUILD)/pins_gen.o
 $(BUILD)/$(FATFS_DIR)/ff.o: COPT += -Os
 $(filter $(PY_BUILD)/../extmod/vfs_fat_%.o, $(PY_O)): COPT += -Os
 
-.phony: all flash sd binary hex
+.PHONY: all flash sd binary hex
 
 all: binary hex