diff --git a/server/services/services_test.go b/server/services/services_test.go
index 624cde7..22e35d5 100644
--- a/server/services/services_test.go
+++ b/server/services/services_test.go
@@ -393,4 +393,69 @@ func TestSetVote(t *testing.T) {
     if expected_non_member_votes != 5 || expected_member_votes != 4 {
         t.Errorf("Expected %d non-member votes and %d member votes, but got %d non-member votes and %d member votes", 4+1, 3+1, expected_non_member_votes, expected_member_votes)
     }
+}
+
+func TestVoterAlreadyVoted(t *testing.T) {
+    // Preload the database with members, polls, and voters
+    tmp_db, err := os.CreateTemp("", "vote_test.*.db")
+    if err != nil {
+        t.Fatalf("Failed to create temporary database: %v", err)
+    }
+    defer os.Remove(tmp_db.Name())
+
+    init_conf := &config.Config{
+        DBPath: string(tmp_db.Name()),
+    }
+    config.SetConfig(init_conf)
+
+    err = PreLoadDB()
+    if err != nil {
+        t.Fatalf("Failed to preload database: %v", err)
+    }
+
+    // Add a non-member vote
+    random_email := RandString(10) + "@mail.me"
+    vote := &models.Vote{
+        PollId: 1,
+        Email: random_email,
+        Vote: true,
+    }
+    err = SetVote(vote)
+    if err != nil {
+        t.Fatalf("Failed to set non-member vote: %v", err)
+    }
+
+    // Add a member vote
+    member_email := "test100@mail.me"
+    vote = &models.Vote{
+        PollId: 1,
+        Email: member_email,
+        Vote: true,
+    }
+    err = SetVote(vote)
+    if err != nil {
+        t.Fatalf("Failed to set member vote: %v", err)
+    }
+
+    // Attempt to add another non-member vote
+    vote = &models.Vote{
+        PollId: 1,
+        Email: random_email,
+        Vote: true,
+    }
+    err = SetVote(vote)
+    if err != ErrVoterAlreadyVoted {
+        t.Fatalf("Expected ErrVoterAlreadyVoted, but got %v", err)
+    }
+
+    // Attempt to add another member vote
+    vote = &models.Vote{
+        PollId: 1,
+        Email: member_email,
+        Vote: true,
+    }
+    err = SetVote(vote)
+    if err != ErrVoterAlreadyVoted {
+        t.Fatalf("Expected ErrVoterAlreadyVoted, but got %v", err)
+    }
 }
\ No newline at end of file