diff --git a/R/RMS.R b/R/RMS.R
index b3188fcd045518458cec57415c4bcd7da3b5621a..2c77d0a818e5794af3074137b59ad0e181aa87d0 100644
--- a/R/RMS.R
+++ b/R/RMS.R
@@ -255,8 +255,10 @@ RMS <- function(exp, obs, time_dim = 'sdate', dat_dim = 'dataset',
   # Remove nexp and nobs if dat_dim = NULL
   if (is.null(dat_dim)) {
     dim(rms) <- NULL
-    dim(conf.lower) <- NULL
-    dim(conf.upper) <- NULL
+    if (conf) {
+      dim(conf.lower) <- NULL
+      dim(conf.upper) <- NULL
+    }
   }
 
   ###################################
diff --git a/tests/testthat/test-RMS.R b/tests/testthat/test-RMS.R
index f69cfd8a1de8e4db627dcfb5e9d0e0ca2a845080..aac0672547c71a1a94dc56332f0d4c44f97af905 100644
--- a/tests/testthat/test-RMS.R
+++ b/tests/testthat/test-RMS.R
@@ -205,6 +205,10 @@ test_that("4. Output checks: dat3", {
   c(1.6458118, 0.8860392, 0.8261295, 1.1681939, 2.1693538, 1.3064454, 0.5384229, 1.1215333),
   tolerance = 0.00001
   )
+  expect_equal(
+  dim(RMS(exp3, obs3, dat_dim = NULL, conf = FALSE)$rms),
+  c(ftime = 2, lon = 1, lat = 4)
+  )
 })
 
 ##############################################
\ No newline at end of file