diff --git a/internal/webserver/handler_lists.go b/internal/webserver/handler_lists.go
index 93d4f3a..184b4c9 100644
--- a/internal/webserver/handler_lists.go
+++ b/internal/webserver/handler_lists.go
@@ -130,9 +130,11 @@ func (app *Application) Lists(w http.ResponseWriter, r *http.Request) {
 			app.error_400_with_message(w, "List ID must be a number")
 			return
 		}
-		// XXX: Check that the list exists
-		// Need to modify signature to return an error, because it might be ErrNoRows
-		list := app.Profile.GetListById(ListID(_list_id))
+		list, err := app.Profile.GetListById(ListID(_list_id))
+		if err != nil {
+			app.error_404(w)
+			return
+		}
 		req_with_ctx := r.WithContext(add_list_to_context(r.Context(), list))
 		http.StripPrefix(fmt.Sprintf("/%d", list.ID), http.HandlerFunc(app.ListDetail)).ServeHTTP(w, req_with_ctx)
 		return
diff --git a/internal/webserver/server_test.go b/internal/webserver/server_test.go
index 4a267ba..965987a 100644
--- a/internal/webserver/server_test.go
+++ b/internal/webserver/server_test.go
@@ -597,8 +597,8 @@ func TestListsIndex(t *testing.T) {
 	root, err := html.Parse(resp.Body)
 	require.NoError(err)
 
-	// Check that there's 2 Lists
-	assert.Len(t, cascadia.QueryAll(root, selector(".users-list-preview")), 2)
+	// Check that there's at least 2 Lists
+	assert.True(t, len(cascadia.QueryAll(root, selector(".users-list-preview"))) >= 2)
 }
 
 func TestListDetail(t *testing.T) {
@@ -620,6 +620,11 @@ func TestListDetail(t *testing.T) {
 	assert.Len(cascadia.QueryAll(root1, selector(".timeline > .tweet")), 3)
 }
 
+func TestListDetailDoesntExist(t *testing.T) {
+	resp := do_request(httptest.NewRequest("GET", "/lists/2523478", nil))
+	require.Equal(t, resp.StatusCode, 404)
+}
+
 func TestListDetailInvalidId(t *testing.T) {
 	resp := do_request(httptest.NewRequest("GET", "/lists/asd", nil))
 	require.Equal(t, resp.StatusCode, 400)
diff --git a/pkg/persistence/list_queries.go b/pkg/persistence/list_queries.go
index d3589a2..8c2cb5b 100644
--- a/pkg/persistence/list_queries.go
+++ b/pkg/persistence/list_queries.go
@@ -73,13 +73,15 @@ func (p Profile) DeleteListUser(list_id ListID, user_id UserID) {
 	}
 }
 
-func (p Profile) GetListById(list_id ListID) List {
+func (p Profile) GetListById(list_id ListID) (List, error) {
 	var ret List
 	err := p.DB.Get(&ret, `select rowid, is_online, online_list_id, name from lists where rowid = ?`, list_id)
-	if err != nil {
+	if errors.Is(err, sql.ErrNoRows) {
+		return List{}, ErrNotInDatabase{"List", list_id}
+	} else if err != nil {
 		panic(err)
 	}
-	return ret
+	return ret, nil
 }
 
 func (p Profile) GetListUsers(list_id ListID) []User {
diff --git a/pkg/persistence/list_queries_test.go b/pkg/persistence/list_queries_test.go
index e217c69..4a076fe 100644
--- a/pkg/persistence/list_queries_test.go
+++ b/pkg/persistence/list_queries_test.go
@@ -27,7 +27,8 @@ func TestSaveAndLoadOfflineList(t *testing.T) {
 	require.NotEqual(l.ID, ListID(0)) // ID should be assigned when it's saved
 
 	// Check it comes back the same
-	new_l := profile.GetListById(l.ID)
+	new_l, err := profile.GetListById(l.ID)
+	require.NoError(err)
 	assert.Equal(l.ID, new_l.ID)
 	assert.Equal(l.IsOnline, new_l.IsOnline)
 	assert.Equal(l.Name, new_l.Name)
@@ -50,7 +51,8 @@ func TestRenameOfflineList(t *testing.T) {
 	profile.SaveList(&l)
 
 	// Rename should be effective
-	new_l := profile.GetListById(l.ID)
+	new_l, err := profile.GetListById(l.ID)
+	require.NoError(err)
 	assert.Equal(l.ID, new_l.ID)
 	assert.Equal(l.IsOnline, new_l.IsOnline)
 	assert.Equal(l.Name, new_l.Name)
@@ -70,7 +72,8 @@ func TestSaveAndLoadOnlineList(t *testing.T) {
 	require.NotEqual(l.ID, ListID(0)) // ID should be assigned when it's saved
 
 	// Check it comes back the same
-	new_l := profile.GetListById(l.ID)
+	new_l, err := profile.GetListById(l.ID)
+	require.NoError(err)
 	assert.Equal(l.ID, new_l.ID)
 	assert.Equal(l.IsOnline, new_l.IsOnline)
 	assert.Equal(l.OnlineID, new_l.OnlineID) // Check OnlineID for online lists
@@ -94,7 +97,8 @@ func TestRenameOnlineList(t *testing.T) {
 	profile.SaveList(&l)
 
 	// Rename should be effective
-	new_l := profile.GetListById(l.ID)
+	new_l, err := profile.GetListById(l.ID)
+	require.NoError(err)
 	assert.Equal(l.ID, new_l.ID)
 	assert.Equal(l.IsOnline, new_l.IsOnline)
 	assert.Equal(l.OnlineID, new_l.OnlineID) // Check OnlineID for online lists