diff --git a/R/g_lineplot.R b/R/g_lineplot.R
index 615ad675c6..e2277122a9 100644
--- a/R/g_lineplot.R
+++ b/R/g_lineplot.R
@@ -512,10 +512,10 @@ control_lineplot_vars <- function(x = "AVISIT", y = "AVAL", group_var = "ARM", p
checkmate::assert_string(x)
checkmate::assert_string(y)
- checkmate::assert_string(group_var, na.ok = TRUE)
- checkmate::assert_string(subject_var, na.ok = TRUE)
- checkmate::assert_string(paramcd, na.ok = TRUE)
- checkmate::assert_string(y_unit, na.ok = TRUE)
+ checkmate::assert_string(group_var, na.ok = TRUE, null.ok = TRUE)
+ checkmate::assert_string(subject_var, na.ok = TRUE, null.ok = TRUE)
+ checkmate::assert_string(paramcd, na.ok = TRUE, null.ok = TRUE)
+ checkmate::assert_string(y_unit, na.ok = TRUE, null.ok = TRUE)
variables <- c(x = x, y = y, group_var = group_var, paramcd = paramcd, y_unit = y_unit, subject_var = subject_var)
return(variables)
diff --git a/tests/testthat/_snaps/bland-altman/g_bland_altman.svg b/tests/testthat/_snaps/bland-altman/g_bland_altman.svg
index 3daf0fe688..a5bfd8ebbf 100644
--- a/tests/testthat/_snaps/bland-altman/g_bland_altman.svg
+++ b/tests/testthat/_snaps/bland-altman/g_bland_altman.svg
@@ -24,80 +24,80 @@
-
-
+
+
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-lower limits of agreement
-upper limits of agreement
-mean of difference between two measures
--2.09
-2.49
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+lower limits of agreement
+upper limits of agreement
+mean of difference between two measures
+-2.09
+2.49
--2
-0
-2
-
-
-
-
-
-
-
-
-
--1.0
--0.5
-0.0
-0.5
-1.0
-1.5
-Average of two measures
-Difference between two measures
+-2
+0
+2
+
+
+
+
+
+
+
+
+
+-1.0
+-0.5
+0.0
+0.5
+1.0
+1.5
+Average of two measures
+Difference between two measures
diff --git a/tests/testthat/_snaps/g_lineplot/g_lineplot_w_stats.svg b/tests/testthat/_snaps/g_lineplot/g_lineplot_w_stats.svg
index 7899d16630..3e60bd25ee 100644
--- a/tests/testthat/_snaps/g_lineplot/g_lineplot_w_stats.svg
+++ b/tests/testthat/_snaps/g_lineplot/g_lineplot_w_stats.svg
@@ -280,13 +280,13 @@
A: Drug X
-Mean 95% CI
+Mean 80% CI
Mean
n
-Mean 95% CI
+Mean 80% CI
Mean
n
-Mean 95% CI
+Mean 80% CI
Mean
n