diff --git a/R/NcReadDims.R b/R/NcReadDims.R
index 660b4efe20e64d9194a22100846d7bb6831bfe5c..5d2d87cd395b7c13a6c569ca3b2567064bb75e82 100644
--- a/R/NcReadDims.R
+++ b/R/NcReadDims.R
@@ -52,8 +52,7 @@ NcReadDims <- function(file_to_read, var_names = NULL) {
       new_dim <- c(var = 1)
       found_dims <- c(new_dim, found_dims)
       if (!is.null(dims)) {
-        dims <- .MergeArrayDims(dims, found_dims)
-        dims <- pmax(dims[[1]], dims[[2]])
+        dims <- .MergeArrayDims(dims, found_dims)[[3]]
         dims['var'] <- dims['var'] + 1
       } else {
         dims <- found_dims
diff --git a/R/Utils.R b/R/Utils.R
index cc9b059ba9b5844e4446ed7552820299ea8b45be..fde2c95c2599850b35bb9f56c6c4b63714cf4990 100644
--- a/R/Utils.R
+++ b/R/Utils.R
@@ -131,6 +131,11 @@
 # It expects as inputs two named numeric vectors, and it extends them
 # with dimensions of length 1 until an ordered common dimension
 # format is reached.
+# The first output is dims1 extended with 1s.
+# The second output is dims2 extended with 1s.
+# The third output is a merged dimension vector. If dimensions with
+# the same name are found in the two inputs, and they have a different
+# length, the maximum is taken.
 .MergeArrayDims <- function(dims1, dims2) {
   new_dims1 <- c()
   new_dims2 <- c()
@@ -158,7 +163,7 @@
     new_dims1 <- c(new_dims1, dims_to_add)
     new_dims2 <- c(new_dims2, dims2)
   }
-  list(new_dims1, new_dims2)
+  list(new_dims1, new_dims2, pmax(new_dims1, new_dims2))
 }
 
 # This function takes two named arrays and merges them, filling with