diff --git a/R/Start.R b/R/Start.R
index c7cc0ff28a4163270f3158bda5ad822bdf7b4c40..5bb0bda2706c333d950b23acc6b8e9a9ea91b1e4 100644
--- a/R/Start.R
+++ b/R/Start.R
@@ -2048,8 +2048,10 @@ Start <- function(..., # dim = indices/selectors,
         # Not all the inner dims are defined in Start() call
         if (!all(names(data_dims) %in% expected_inner_dims[[i]])) {
           tmp <- names(data_dims)[which(!names(data_dims) %in% expected_inner_dims[[i]])]
-          if (data_dims[tmp] != 1) {
-            stop("The dimension '", tmp, "' is found in the file ", file_path,
+          undefined_dims <- tmp[data_dims[tmp] != 1]
+          if (length(undefined_dims > 0)) {
+            stop("The dimension(s) '", paste(undefined_dims, collapse = ", "),
+                 "' is found in the file ", file_path,
                  " but not defined in the Start call.")
           }
         }