diff --git a/src/utils/convertToCsv.ts b/src/utils/convertToCsv.ts
index 73af3ba..f6a1a5b 100644
--- a/src/utils/convertToCsv.ts
+++ b/src/utils/convertToCsv.ts
@@ -10,7 +10,7 @@ export const convertToCSV = (
   let headers: string[] = []
   let csvTest
   let invalidString = false
-  const specialMissingValueRegExp = /^[a-z_]{1}$/i
+  const specialMissingValueRegExp = /^[a-z_.]{1}$/i
 
   if (formats) {
     headers = Object.keys(formats).map((key) => `${key}:${formats![key]}`)