diff --git a/test/src/test_Buffer.cc b/test/src/test_Buffer.cc
index b00a57a..76384dc 100644
--- a/test/src/test_Buffer.cc
+++ b/test/src/test_Buffer.cc
@@ -138,11 +138,14 @@ TEST(BufferTest, adds_a_newline_after_inserted_character_when_inserting_in_an_em
     Buffer b;
     auto it = b.add_cursor();
     EXPECT_EQ(0u, it->offset());
+    EXPECT_FALSE(it->valid());
 
     b.enter_insert_mode();
     b.insert_code_point(*it, C('J'));
     EXPECT_EQ(ss("J\n"), b.get_string());
     EXPECT_EQ(C('\n'), **it);
+    EXPECT_TRUE(it->valid());
+    EXPECT_EQ(0u, it->line());
     b.exit_insert_mode();
 }
 
@@ -465,3 +468,31 @@ TEST(BufferTest, inserting_at_beginning_and_end_of_line_in_insert_mode_creates_p
     b.redo();
     EXPECT_EQ("12abc34\ndef\n", b.get_string());
 }
+
+TEST(BufferTest, inserts_and_undoes_properly_starting_from_empty_buffer)
+{
+    Buffer b;
+    auto it = b.add_cursor();
+
+    b.enter_insert_mode();
+    EXPECT_FALSE(it->valid());
+    b.insert_code_point(*it, C('1'));
+    EXPECT_TRUE(it->valid());
+    EXPECT_EQ(0u, it->line());
+    b.insert_code_point(*it, C('\n'));
+    EXPECT_EQ(1u, it->line());
+    b.insert_code_point(*it, C('2'));
+    EXPECT_EQ(1u, it->line());
+    b.insert_code_point(*it, C('\n'));
+    EXPECT_EQ(2u, it->line());
+    b.insert_code_point(*it, C('3'));
+    EXPECT_EQ(2u, it->line());
+    b.exit_insert_mode();
+
+    EXPECT_EQ(2u, it->line());
+    EXPECT_EQ("1\n2\n3\n", b.get_string());
+
+    b.undo();
+    EXPECT_EQ("", b.get_string());
+    EXPECT_EQ(0u, it->line());
+}