diff --git a/telegram/formatter/formatter_test.go b/telegram/formatter/formatter_test.go
index 63337d6..8453851 100644
--- a/telegram/formatter/formatter_test.go
+++ b/telegram/formatter/formatter_test.go
@@ -206,3 +206,66 @@ func TestSortEmpty(t *testing.T) {
 		t.Errorf("Empty entities set sorting error: %#v", entities)
 	}
 }
+
+func TestNoFormattingXEP0393(t *testing.T) {
+	markup := Format("abc\ndef", []*client.TextEntity{}, EntityToXEP0393)
+	if markup != "abc\ndef" {
+		t.Errorf("No formatting expected, but: %v", markup)
+	}
+}
+
+func TestFormattingXEP0393Simple(t *testing.T) {
+	markup := Format("👙🐧🐖", []*client.TextEntity{
+		&client.TextEntity{
+			Offset: 2,
+			Length: 4,
+			Type:   &client.TextEntityTypeBold{},
+		},
+	}, EntityToXEP0393)
+	if markup != "👙*🐧🐖*" {
+		t.Errorf("Wrong simple formatting: %v", markup)
+	}
+}
+
+func TestFormattingXEP0393Adjacent(t *testing.T) {
+	markup := Format("a👙🐧🐖", []*client.TextEntity{
+		&client.TextEntity{
+			Offset: 3,
+			Length: 2,
+			Type:   &client.TextEntityTypeItalic{},
+		},
+		&client.TextEntity{
+			Offset: 5,
+			Length: 2,
+			Type: &client.TextEntityTypeTextUrl{
+				Url: "https://narayana.im/",
+			},
+		},
+	}, EntityToXEP0393)
+	if markup != "a👙_🐧_🐖 <https://narayana.im/>" {
+		t.Errorf("Wrong adjacent formatting: %v", markup)
+	}
+}
+
+func TestFormattingXEP0393AdjacentAndNested(t *testing.T) {
+	markup := Format("👙🐧🐖", []*client.TextEntity{
+		&client.TextEntity{
+			Offset: 0,
+			Length: 4,
+			Type:   &client.TextEntityTypePre{},
+		},
+		&client.TextEntity{
+			Offset: 0,
+			Length: 2,
+			Type:   &client.TextEntityTypeBold{},
+		},
+		&client.TextEntity{
+			Offset: 4,
+			Length: 2,
+			Type:   &client.TextEntityTypeItalic{},
+		},
+	}, EntityToXEP0393)
+	if markup != "\n```\n*👙*🐧\n```\n_🐖_" {
+		t.Errorf("Wrong adjacent&nested formatting: %v", markup)
+	}
+}