diff --git a/Makefile b/Makefile
index 2040beb..1e8363a 100644
--- a/Makefile
+++ b/Makefile
@@ -11,31 +11,31 @@ prepare:
 	cd esp-idf; bash install.sh
 
 clean:
-	rm -rf $(BUILDDIR)
+	rm -rf "$(BUILDDIR)"
 
 build:
-	source $(IDF_PATH)/export.sh && idf.py build
+	source "$(IDF_PATH)/export.sh" && idf.py build
 
 flash: build
-	source $(IDF_PATH)/export.sh && idf.py flash -p $(PORT)
+	source "$(IDF_PATH)/export.sh" && idf.py flash -p $(PORT)
 
 erase:
-	source $(IDF_PATH)/export.sh && idf.py erase-flash -p $(PORT)
+	source "$(IDF_PATH)/export.sh" && idf.py erase-flash -p $(PORT)
 
 monitor:
-	source $(IDF_PATH)/export.sh && idf.py monitor -p $(PORT)
+	source "$(IDF_PATH)/export.sh" && idf.py monitor -p $(PORT)
 
 menuconfig:
-	source $(IDF_PATH)/export.sh && idf.py menuconfig
+	source "$(IDF_PATH)/export.sh" && idf.py menuconfig
 
 image:
-	cd $(BUILDDIR); dd if=/dev/zero bs=1M count=16 of=flash.bin
-	cd $(BUILDDIR); dd if=bootloader/bootloader.bin bs=1 seek=4096 of=flash.bin conv=notrunc
-	cd $(BUILDDIR); dd if=partition_table/partition-table.bin bs=1 seek=36864 of=flash.bin conv=notrunc
-	cd $(BUILDDIR); dd if=main.bin bs=1 seek=65536 of=flash.bin conv=notrunc
+	cd "$(BUILDDIR)"; dd if=/dev/zero bs=1M count=16 of=flash.bin
+	cd "$(BUILDDIR)"; dd if=bootloader/bootloader.bin bs=1 seek=4096 of=flash.bin conv=notrunc
+	cd "$(BUILDDIR)"; dd if=partition_table/partition-table.bin bs=1 seek=36864 of=flash.bin conv=notrunc
+	cd "$(BUILDDIR)"; dd if=main.bin bs=1 seek=65536 of=flash.bin conv=notrunc
 
 qemu: image
-	cd $(BUILDDIR); qemu-system-xtensa -nographic -machine esp32 -drive 'file=flash.bin,if=mtd,format=raw'
+	cd "$(BUILDDIR)"; qemu-system-xtensa -nographic -machine esp32 -drive 'file=flash.bin,if=mtd,format=raw'
 
 install: flash