diff --git a/Makefile b/Makefile
index 6f1bb20..f797024 100644
--- a/Makefile
+++ b/Makefile
@@ -104,6 +104,8 @@ OBJCOPY = $(ARCH)objcopy
 OPTIMIZE = -Os -ffunction-sections -finline-functions-called-once -mcall-prologues
 # OPTIMIZE = -O0
 CFLAGS = -g -Wall -Wstrict-prototypes $(OPTIMIZE) -mmcu=$(MCU_TARGET) $(DEFS) -std=gnu99 -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums -save-temps -Winline
+CFLAGS += -fno-move-loop-invariants
+CFLAGS += -fno-tree-scev-cprop
 LDFLAGS = -Wl,--as-needed -Wl,--gc-sections
 LIBS = -lm
 LIBDEPS =