diff --git a/service.go b/service.go
index c4fd078..188de6a 100644
--- a/service.go
+++ b/service.go
@@ -472,11 +472,32 @@ func (s *Service) getEffectiveContextGenderLocationAndFormality(data any) (strin
 }
 
 func (s *Service) getEffectiveContextExtra(data any) map[string]any {
-	ctx, ok := data.(*TranslationContext)
-	if !ok || ctx == nil || len(ctx.Extra) == 0 {
+	switch v := data.(type) {
+	case *TranslationContext:
+		if v == nil || len(v.Extra) == 0 {
+			return nil
+		}
+		return v.Extra
+	case map[string]any:
+		if len(v) == 0 {
+			return nil
+		}
+		extra := make(map[string]any, len(v))
+		for key, value := range v {
+			switch key {
+			case "Context", "Gender", "Location", "Formality":
+				continue
+			default:
+				extra[key] = value
+			}
+		}
+		if len(extra) == 0 {
+			return nil
+		}
+		return extra
+	default:
 		return nil
 	}
-	return ctx.Extra
 }
 
 func (s *Service) getEffectiveFormality(data any) Formality {
diff --git a/service_test.go b/service_test.go
index 47df379..250fd4c 100644
--- a/service_test.go
+++ b/service_test.go
@@ -349,6 +349,31 @@ func TestServiceTranslationContextExtrasInLookup(t *testing.T) {
 	}
 }
 
+func TestServiceMapContextExtrasInLookup(t *testing.T) {
+	svc, err := New()
+	if err != nil {
+		t.Fatalf("New() failed: %v", err)
+	}
+
+	svc.AddMessages("en", map[string]string{
+		"welcome._greeting":                   "hello",
+		"welcome._greeting._region._europe":   "bonjour",
+		"welcome._greeting._region._americas": "howdy",
+	})
+
+	if got := svc.T("welcome", map[string]any{"Context": "greeting"}); got != "hello" {
+		t.Errorf("T(welcome, map[Context:greeting]) = %q, want %q", got, "hello")
+	}
+
+	if got := svc.T("welcome", map[string]any{"Context": "greeting", "region": "europe"}); got != "bonjour" {
+		t.Errorf("T(welcome, map[Context:greeting region:europe]) = %q, want %q", got, "bonjour")
+	}
+
+	if got := svc.T("welcome", map[string]any{"Context": "greeting", "region": "americas"}); got != "howdy" {
+		t.Errorf("T(welcome, map[Context:greeting region:americas]) = %q, want %q", got, "howdy")
+	}
+}
+
 func TestServiceDefaultLocationAppliesToMapData(t *testing.T) {
 	svc, err := New()
 	if err != nil {