diff --git a/lns.go b/lns.go
index a44288f..2f24aac 100644
--- a/lns.go
+++ b/lns.go
@@ -199,9 +199,14 @@ func LookupCatalogName[T any](
 	byLabel func(string) (T, bool),
 	byHash func(primitives.Hash) (T, bool),
 ) (T, bool) {
+	var zero T
+
+	if byLabel == nil || byHash == nil {
+		return zero, false
+	}
+
 	label, ok := nameutil.CatalogLabel(name)
 	if !ok {
-		var zero T
 		return zero, false
 	}
 
@@ -213,7 +218,6 @@ func LookupCatalogName[T any](
 
 	normalized, ok := nameutil.Canonicalize(name)
 	if !ok {
-		var zero T
 		return zero, false
 	}
 
diff --git a/lns_package_test.go b/lns_package_test.go
index a46cdfb..8f380eb 100644
--- a/lns_package_test.go
+++ b/lns_package_test.go
@@ -350,6 +350,26 @@ func TestLookupCatalogNamePreservesDottedLabels(t *testing.T) {
 	}
 }
 
+func TestLookupCatalogNameNilCallbacks(t *testing.T) {
+	if got, ok := LookupCatalogName[string]("foo", nil, nil); ok || got != "" {
+		t.Fatalf("LookupCatalogName with nil callbacks = (%q, %v), want (\"\", false)", got, ok)
+	}
+
+	if got, ok := GetLookupCatalogName[string]("foo", nil, nil); ok || got != "" {
+		t.Fatalf("GetLookupCatalogName with nil callbacks = (%q, %v), want (\"\", false)", got, ok)
+	}
+
+	svc := NewService(nil)
+
+	if got, ok := svc.LookupCatalogName("foo", nil, nil); ok || got != nil {
+		t.Fatalf("svc.LookupCatalogName with nil callbacks = (%v, %v), want (nil, false)", got, ok)
+	}
+
+	if got, ok := svc.GetLookupCatalogName("foo", nil, nil); ok || got != nil {
+		t.Fatalf("svc.GetLookupCatalogName with nil callbacks = (%v, %v), want (nil, false)", got, ok)
+	}
+}
+
 func TestPackageTypeTables(t *testing.T) {
 	if len(Types) == 0 || len(TypesByVal) == 0 {
 		t.Fatal("type lookup tables should not be empty")