diff --git a/internal/requests/radarr/client.go b/internal/requests/radarr/client.go
index df4f08ab..7f6f7624 100644
--- a/internal/requests/radarr/client.go
+++ b/internal/requests/radarr/client.go
@@ -140,14 +140,13 @@ func (c *Client) CheckMovieStatus(ctx context.Context, req mediarequests.Request
 func (c *Client) lookupMovie(ctx context.Context, client *arrclient.Client, tmdbID int) (movieResource, error) {
 	values := url.Values{}
 	values.Set("tmdbId", strconv.Itoa(tmdbID))
-	var matches []movieResource
-	if err := client.GetJSON(ctx, "/api/v3/movie/lookup/tmdb?"+values.Encode(), &matches); err != nil {
+	// Radarr's /api/v3/movie/lookup/tmdb returns a single MovieResource, unlike
+	// /api/v3/movie/lookup which returns an array. Missing IDs return non-2xx
+	// (handled as HTTPError upstream), so a successful response is the movie.
+	var movie movieResource
+	if err := client.GetJSON(ctx, "/api/v3/movie/lookup/tmdb?"+values.Encode(), &movie); err != nil {
 		return movieResource{}, err
 	}
-	if len(matches) == 0 {
-		return movieResource{}, fmt.Errorf("radarr: no movie found for tmdb_id %d", tmdbID)
-	}
-	movie := matches[0]
 	if movie.TMDBID == 0 {
 		movie.TMDBID = tmdbID
 	}
diff --git a/internal/requests/radarr/client_test.go b/internal/requests/radarr/client_test.go
index d9592334..63e11d0b 100644
--- a/internal/requests/radarr/client_test.go
+++ b/internal/requests/radarr/client_test.go
@@ -37,7 +37,7 @@ func TestSubmitMovieAddsLookupResult(t *testing.T) {
 			if got := r.URL.Query().Get("tmdbId"); got != "550" {
 				t.Fatalf("lookup tmdbId = %q, want 550", got)
 			}
-			w.Write([]byte(`[{"title":"Fight Club","tmdbId":550,"titleSlug":"fight-club"}]`))
+			w.Write([]byte(`{"title":"Fight Club","tmdbId":550,"titleSlug":"fight-club"}`))
 			return
 		}
 		t.Fatalf("unexpected request %s %s", r.Method, r.URL.String())
@@ -78,7 +78,7 @@ func TestSubmitMovieRecoversFromEmptyAddResponse(t *testing.T) {
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		switch r.URL.Path {
 		case "/api/v3/movie/lookup/tmdb":
-			w.Write([]byte(`[{"title":"Fight Club","tmdbId":550,"titleSlug":"fight-club"}]`))
+			w.Write([]byte(`{"title":"Fight Club","tmdbId":550,"titleSlug":"fight-club"}`))
 		case "/api/v3/movie":
 			if r.Method == http.MethodPost {
 				w.WriteHeader(http.StatusCreated)
@@ -125,7 +125,7 @@ func TestSubmitMovieFallsBackWhenEmptyResponseAndLookupFails(t *testing.T) {
 	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		switch r.URL.Path {
 		case "/api/v3/movie/lookup/tmdb":
-			w.Write([]byte(`[{"title":"Fight Club","tmdbId":550,"titleSlug":"fight-club"}]`))
+			w.Write([]byte(`{"title":"Fight Club","tmdbId":550,"titleSlug":"fight-club"}`))
 		case "/api/v3/movie":
 			if r.Method == http.MethodPost {
 				w.WriteHeader(http.StatusCreated)