diff --git a/R/PeriodPET.R b/R/PeriodPET.R
index 27d6ecaeeed9d7a9e778426495348ebcd9f519ab..02ddb5f32c9e658a21d467b4b998fdefaa4dea11 100644
--- a/R/PeriodPET.R
+++ b/R/PeriodPET.R
@@ -91,8 +91,12 @@ CST_PeriodPET <- function(data, pet_method = 'hargreaves',
   source_files <- lapply(data, function(x) {x$attrs$source_files})
   coords <- data[[1]]$coords
   Dates <- data[[1]]$attrs$Dates
+  
   metadata <- data[[1]]$attrs$Variable$metadata
-  metadata_names <- intersect(names(dim(res)), names(metadata))
+  metadata[["PET"]]$longname <- "Potential evapotranspiration"
+  metadata[["PET"]]$units <- "mm"
+
+  metadata_names <- c(intersect(names(dim(res)), names(metadata)), "PET")
   suppressWarnings(
     res <- s2dv_cube(data = res, coords = coords, 
                      varName = paste0('PET'), 
@@ -383,4 +387,4 @@ PeriodPET <- function(data, dates, lat, pet_method = 'hargreaves',
     pet <- array(pet[which(mask_dates == 1)], dim = dims)
   }
   return(pet)
-}
\ No newline at end of file
+}