diff --git a/R/oa2df.R b/R/oa2df.R
index 516f66d..41d0968 100644
--- a/R/oa2df.R
+++ b/R/oa2df.R
@@ -200,6 +200,9 @@ works2df <- function(data, abstract = TRUE, verbose = TRUE,
       fields$type,
       SIMPLIFY = FALSE
     )
+    if (!is.null(sim_fields$publication_date)) {
+      sim_fields$publication_date <- as.Date(sim_fields$publication_date)
+    }
 
     author <- venue <- ab <- NULL