diff --git a/.github/workflows/run_tests_octave.yml b/.github/workflows/run_tests_octave.yml
index 959cc9d..5d5641b 100644
--- a/.github/workflows/run_tests_octave.yml
+++ b/.github/workflows/run_tests_octave.yml
@@ -1,6 +1,9 @@
 ---
 name: tests and coverage with octave
 
+env:
+  OCTFLAGS: --no-gui --no-window-system --silent
+
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
@@ -18,7 +21,7 @@ on:
   workflow_dispatch:
 
 jobs:
-  tests_matlab:
+  tests_octave:
     runs-on: ubuntu-latest
 
     steps:
@@ -66,7 +69,6 @@ jobs:
         octave $OCTFLAGS --eval "addpath(fullfile(pwd, 'tests', 'utils')); savepath();"
         octave $OCTFLAGS --eval "cd(fullfile(getenv('GITHUB_WORKSPACE'), '.github', 'workflows')); run tests_matlab;"
 
-
     - name: Code coverage
       uses: codecov/codecov-action@v4
       with:
diff --git a/.github/workflows/tests_matlab.m b/.github/workflows/tests_matlab.m
index 21f8fb4..437e1d1 100644
--- a/.github/workflows/tests_matlab.m
+++ b/.github/workflows/tests_matlab.m
@@ -8,6 +8,7 @@
 addpath(fullfile(root_dir, 'MOcov', 'MOcov'));
 
 cd(fullfile(root_dir, 'MOxUnit', 'MOxUnit'));
+pwd;
 run moxunit_set_path();
 
 cd(fullfile(root_dir));
diff --git a/src/atlas/extractRoiFromAtlas.m b/src/atlas/extractRoiFromAtlas.m
index 0783d86..455a64c 100644
--- a/src/atlas/extractRoiFromAtlas.m
+++ b/src/atlas/extractRoiFromAtlas.m
@@ -39,9 +39,9 @@
   args = inputParser;
 
   addRequired(args, 'outputDir', isChar);
-  addRequired(args, 'atlasName', @(x) isAKnownAtlas(x));
+  addRequired(args, 'atlasName');
   addRequired(args, 'roiName', isChar);
-  addRequired(args, 'hemisphere', @(x) ismember(x, {'L', 'R'}));
+  addRequired(args, 'hemisphere');
 
   parse(args, varargin{:});
 
@@ -50,6 +50,15 @@
   roiName = args.Results.roiName;
   hemisphere = args.Results.hemisphere;
 
+  if ~ismember(hemisphere, {'L', 'R'})
+    msg = sprintf('"hemisphere must be "L" or "R"": %s\nGot: "%s"', ...
+                  hemisphere);
+    bids.internal.error_handling(mfilename(), ...
+                                 'invalidHemisphere', msg, false);
+  end
+
+  isAKnownAtlas(atlasName);
+
   [atlasFile, lut] = getAtlasAndLut(atlasName);
 
   switch lower(atlasName)