diff --git a/components/spiffs/Makefile.projbuild b/components/spiffs/Makefile.projbuild
index 87e1f59ed..83c9d4e30 100644
--- a/components/spiffs/Makefile.projbuild
+++ b/components/spiffs/Makefile.projbuild
@@ -2,21 +2,21 @@ SPIFFSGEN_PY:=$(COMPONENT_PATH)/spiffsgen.py
 SPIFFSGEN_FLASH_IN_PROJECT=
 
 ifdef CONFIG_SPIFFS_USE_MAGIC
-USE_MAGIC = "--use-magic"
+USE_MAGIC := "--use-magic"
 else
-USE_MAGIC = ""
+USE_MAGIC :=
 endif
 
 ifdef CONFIG_SPIFFS_USE_MAGIC_LENGTH
-USE_MAGIC_LEN = "--use-magic-len" 
+USE_MAGIC_LEN := "--use-magic-len" 
 else
-USE_MAGIC_LEN = ""
+USE_MAGIC_LEN :=
 endif
 
 ifdef CONFIG_SPIFFS_FOLLOW_SYMLINKS
-FOLLOW_SYMLINKS = "--follow-symlinks" 
+FOLLOW_SYMLINKS := "--follow-symlinks"
 else
-FOLLOW_SYMLINKS = ""
+FOLLOW_SYMLINKS :=
 endif
 
 # spiffs_create_partition_image