diff --git a/gridfinity-rebuilt-utility.scad b/gridfinity-rebuilt-utility.scad
index 80f28e2..22a27a1 100644
--- a/gridfinity-rebuilt-utility.scad
+++ b/gridfinity-rebuilt-utility.scad
@@ -230,7 +230,7 @@ module gridfinityBase(gx, gy, l, dx, dy, hole_options=bundle_hole_options(), off
         if(only_corners) {
             difference(){
                 pattern_linear(gx/dbnx, gy/dbny, dbnx*l, dbny*l)
-                block_base(gx, gy, l, dbnx, dbny, 0, off);
+                block_base(gx, gy, l, dbnx, dbny, bundle_hole_options(), off);
 
                 copy_mirror([0, 1, 0]) {
                     copy_mirror([1, 0, 0]) {
diff --git a/tests/openscad_runner.py b/tests/openscad_runner.py
index c73987d..1d150bd 100644
--- a/tests/openscad_runner.py
+++ b/tests/openscad_runner.py
@@ -109,7 +109,7 @@ class OpenScadRunner:
     TOP_ANGLE_CAMERA = CameraArguments(Vec3(0,0,0),Vec3(45,0,45),150)
 
     common_arguments = [
-        #'--hardwarnings', // Does not work when setting variables by using functions
+        #'--hardwarnings', # Does not work when setting variables by using functions
         '--enable=fast-csg',
         '--enable=predictible-output',
         '--imgsize=1280,720',
@@ -127,9 +127,9 @@ class OpenScadRunner:
         self.camera_arguments = None
         self.parameters = None
 
-    def create_image(self, args: [str], image_file_name: str):
+    def create_image(self, args: [str], image_file_name: str) -> subprocess.CompletedProcess:
         """
-        Run the code, to create an image.
+        Run the code and create an image.
         @Important The only verification is that no errors occured.
                    There is no verification if the image was created, or the image contents.
         """
@@ -150,6 +150,18 @@ class OpenScadRunner:
                 json.dump(params, file, sort_keys=True, indent=2, cls=DataClassJSONEncoder)
                 file.close()
                 command_arguments += ["-p", file.name, "-P", "python_generated"]
-                return subprocess.run([self.openscad_binary_path]+command_arguments, check=True)
+                return self._run(command_arguments)
         else:
-            return subprocess.run([self.openscad_binary_path]+command_arguments, check=True)
+            return self._run(command_arguments)
+
+    def _run(self, args: [str]) -> subprocess.CompletedProcess:
+        """
+        Run openscad with the passed in arguments.
+        """
+        output = subprocess.run([self.openscad_binary_path]+args, capture_output=True)
+        error_strings = output.stderr.decode().strip().splitlines()
+        if any(line.startswith("ERROR:") for line in error_strings):
+            # OpenSCAD doesn't set an error return if it errors from bad SCAD code!
+            output.returncode = 11
+        output.check_returncode()
+        return output
diff --git a/tests/test_bins.py b/tests/test_bins.py
index 1c922b0..8959eea 100644
--- a/tests/test_bins.py
+++ b/tests/test_bins.py
@@ -37,6 +37,14 @@ class TestBinHoles(unittest.TestCase):
         vars["screw_holes"] = False
         self.scad_runner.create_image([], Path('no_holes.png'))
 
+    def test_only_corner_holes(self):
+        vars = self.scad_runner.parameters
+        vars["refined_holes"] = True
+        vars["magnet_holes"] = False
+        vars["screw_holes"] = False
+        vars["only_corners"] = True
+        self.scad_runner.create_image([], Path('only_corner_holes.png'))
+
     def test_refined_holes(self):
         vars = self.scad_runner.parameters
         vars["refined_holes"] = True