diff --git a/package/base-files/files/lib/functions/caldata.sh b/package/base-files/files/lib/functions/caldata.sh
index 1ff69ce1ae..3bdb1e4dd5 100644
--- a/package/base-files/files/lib/functions/caldata.sh
+++ b/package/base-files/files/lib/functions/caldata.sh
@@ -69,7 +69,7 @@ caldata_valid() {
 	local expected="$1"
 
 	magic=$(hexdump -v -n 2 -e '1/1 "%02x"' /lib/firmware/$FIRMWARE)
-	[[ "$magic" == "$expected" ]]
+	[ "$magic" = "$expected" ]
 	return $?
 }