diff --git a/src/gradescopeapi/classes/_helpers/_course_helpers.py b/src/gradescopeapi/classes/_helpers/_course_helpers.py
index 23ab416..182e4df 100644
--- a/src/gradescopeapi/classes/_helpers/_course_helpers.py
+++ b/src/gradescopeapi/classes/_helpers/_course_helpers.py
@@ -167,8 +167,13 @@ def get_course_members(soup: BeautifulSoup, course_id: str) -> list[Member]:
             data_url: str = rosterName_button.get("data-url", None)
             user_id = data_url.split("user_id=")[-1]
 
-        # fetch number of submissions from table cell
-        num_submissions = int(cells[num_submissions_column].text)
+        # fetch number of submissions from table cell. Some roster layouts have
+        # extra trailing action columns, so the heuristic column index can land
+        # on an empty/non-numeric cell; default to 0 rather than raising.
+        try:
+            num_submissions = int(cells[num_submissions_column].text)
+        except (ValueError, IndexError):
+            num_submissions = 0
 
         # create Member object with all relevant info
         member_list.append(
diff --git a/tests/test_roster_unit.py b/tests/test_roster_unit.py
new file mode 100644
index 0000000..692719e
--- /dev/null
+++ b/tests/test_roster_unit.py
@@ -0,0 +1,65 @@
+"""Unit tests for get_course_members — no network/credentials required.
+
+Builds a roster page from crafted HTML and checks that a roster whose
+heuristic "# submissions" column is empty still parses (count defaults to 0),
+and that a numeric count is read correctly.
+"""
+import json
+
+from bs4 import BeautifulSoup
+
+from gradescopeapi.classes._helpers._course_helpers import get_course_members
+
+
+def _roster_html(rows):
+    headers = "".join(f"<th>h{i}</th>" for i in range(6))  # -> column index 3
+    body = ""
+    for r in rows:
+        cm = json.dumps({
+            "full_name": r["full_name"],
+            "first_name": r["first_name"],
+            "last_name": r["last_name"],
+            "sid": r["sid"],
+        })
+        # 8 cells; index 3 is the heuristic submissions column
+        cells = [
+            f'<td><button class="rosterCell--editIcon" data-cm=\'{cm}\' '
+            f'data-email="{r["email"]}" data-role="{r["role"]}" data-sections="">'
+            f'</button><button class="js-rosterName" '
+            f'data-url="/courses/999/gradebook.json?user_id={r["user_id"]}">'
+            f'{r["full_name"]}</button></td>',
+            "<td>email</td>", "<td>role</td>",
+            f'<td>{r["submissions"]}</td>',  # index 3
+            "<td></td>", "<td></td>", "<td></td>", "<td></td>",
+        ]
+        body += f'<tr class="rosterRow">{"".join(cells)}</tr>'
+    return f'<table class="js-rosterTable"><thead>{headers}</thead><tbody>{body}</tbody></table>'
+
+
+def test_empty_submissions_cell_does_not_crash():
+    rows = [{
+        "full_name": "Ada Lovelace", "first_name": "Ada", "last_name": "Lovelace",
+        "sid": "123", "email": "ada@example.edu", "role": "0",
+        "user_id": "555", "submissions": "",  # empty submissions cell
+    }]
+    soup = BeautifulSoup(_roster_html(rows), "html.parser")
+    members = get_course_members(soup, "999")
+    assert len(members) == 1
+    m = members[0]
+    assert m.email == "ada@example.edu"
+    assert m.role == "Student"
+    assert m.full_name == "Ada Lovelace"
+    assert m.user_id == "555"
+    assert m.num_submissions == 0
+
+
+def test_numeric_submissions_cell_is_parsed():
+    rows = [{
+        "full_name": "Alan Turing", "first_name": "Alan", "last_name": "Turing",
+        "sid": "9", "email": "alan@example.edu", "role": "2",
+        "user_id": "777", "submissions": "5",
+    }]
+    soup = BeautifulSoup(_roster_html(rows), "html.parser")
+    members = get_course_members(soup, "999")
+    assert members[0].num_submissions == 5
+    assert members[0].role == "TA"