diff --git a/R/concept-load.R b/R/concept-load.R
index 2f2c6d7e..66b22c35 100644
--- a/R/concept-load.R
+++ b/R/concept-load.R
@@ -560,9 +560,11 @@ load_concepts.itm <- function(x, patient_ids = NULL, id_type = "icustay",
   res <- merge_patid(res, patient_ids)
   res <- do_callback(x, res)
 
-  if (is_ts_tbl(res)) {
+  if (is_win_tbl(res)) {
+    res <- change_interval(res, interval, c(index_var(res), dur_var(res)), by_ref = TRUE)
+  } else if (is_ts_tbl(res)) {
     res <- change_interval(res, interval, index_var(res), by_ref = TRUE)
-  }
+  } 
 
   res
 }
diff --git a/R/data-load.R b/R/data-load.R
index 711f6d43..c4e04594 100644
--- a/R/data-load.R
+++ b/R/data-load.R
@@ -440,7 +440,7 @@ load_win.src_tbl <- function(x, rows, cols = colnames(x), id_var = id_vars(x),
   time_vars <- setdiff(intersect(time_vars, colnames(res)), dur_var)
 
   res <- change_id(res, id_var, x, cols = time_vars, keep_old_id = FALSE)
-  res <- change_interval(res, interval, time_vars, by_ref = TRUE)
+  res <- change_interval(res, interval, c(time_vars, dur_var), by_ref = TRUE)
 
   res
 }
diff --git a/R/data-utils.R b/R/data-utils.R
index 3e1020d5..7a6aa445 100644
--- a/R/data-utils.R
+++ b/R/data-utils.R
@@ -689,6 +689,34 @@ upgrade_id.ts_tbl <- function(x, target_id, src, cols = time_vars(x), ...) {
   res
 }
 
+#' @rdname change_id
+#' @export
+#'
+upgrade_id.win_tbl <- function(x, target_id, src, cols = time_vars(x), ...) {
+  
+  assert_that(index_var(x) %in% cols)
+  
+  if (!is_one_min(interval(x))) {
+    warn_ricu("Changing the ID of non-minute resolution data will change the
+               interval to 1 minute", class = "non_min_id_change")
+  }
+  
+  sft <- new_names(x)
+  idx <- index_var(x)
+  dur <- dur_var(x)
+  
+  map <- id_map(src, id_vars(x), target_id, sft, idx)
+  
+  res <- map[x, on = c(id_vars(x), index_var(x)), roll = -Inf, rollends = TRUE]
+  res <- res[, c(cols) := lapply(.SD, `-`, get(sft)), .SDcols = cols]
+  
+  res <- as_win_tbl(res, target_id, idx, mins(1L), dur, by_ref = TRUE)
+  res <- rm_cols(res, sft, by_ref = TRUE)
+  
+  res
+}
+
+
 #' @rdname change_id
 #' @export
 #'
diff --git a/R/tbl-utils.R b/R/tbl-utils.R
index ad40ba51..be042cdf 100644
--- a/R/tbl-utils.R
+++ b/R/tbl-utils.R
@@ -501,9 +501,7 @@ change_interval <- function(x, new_interval, cols = time_vars(x),
   assert_that(is_scalar(new_interval), is_interval(new_interval),
               is.flag(by_ref))
 
-  if (!length(cols) ||
-      (is_ts_tbl(x) && all_equal(interval(x), new_interval))) {
-
+  if (!length(cols)) {
     return(x)
   }