diff --git a/r/GetBirthdate.R b/r/GetBirthdate.R
index efe63b12e04c8f7c05078dbcc21c43796d73e5cd..2741b2498984e8d3dc5b34953ae1ea2e2447014f 100644
--- a/r/GetBirthdate.R
+++ b/r/GetBirthdate.R
@@ -26,7 +26,7 @@ getBirthdate <- function(article) {
       birthdate <- substring(birthdate, 2, nchar(birthdate)-1)
     } else {
       # Retrun Null if there is no birthdate
-      return(0)
+      return(Null)
     }
   }