diff --git a/R/format.R b/R/format.R
index cffe4764..6061c87d 100644
--- a/R/format.R
+++ b/R/format.R
@@ -180,7 +180,7 @@ check_formats <- function(.df, format, verbose) {
 
     # check that any variables ending DT, DTM, TM have a format
     if (identical(format_sas, "")) {
-      if (isTRUE(grepl("DT$|DTM$|TM$", colnames(.df)[i]))) {
+      if (isTRUE(grepl("(DT|DTM|TM)$", colnames(.df)[i]))) {
         message <- glue(
           "(xportr::xportr_format) {encode_vars(colnames(.df)[i])} is expected to have a format but does not."
         )