diff --git a/src/core/Buffer.cc b/src/core/Buffer.cc
index 6e2f66c..fe47b15 100644
--- a/src/core/Buffer.cc
+++ b/src/core/Buffer.cc
@@ -24,6 +24,7 @@ void Buffer::load_empty_buffer()
 {
     m_gap_buffer = std::make_shared<GapBuffer>(Encoding::UTF_8);
     m_eol_at_eof = true;
+    m_line_endings = LineEndings::LF;
 }
 
 bool Buffer::load_from_file(const char * filename)
@@ -59,6 +60,7 @@ bool Buffer::load_from_file(const char * filename)
 
     m_gap_buffer = std::make_shared<GapBuffer>(buffer, buffer_size, loaded_size, text_loader.get_encoding());
     m_eol_at_eof = text_loader.get_eol_at_eof();
+    m_line_endings = text_loader.get_line_endings();
 
     return true;
 }
@@ -71,7 +73,39 @@ bool Buffer::write_to_file(const char * filename)
         return false;
     }
 
-    /* TODO */
+    m_gap_buffer->compact();
+
+    GapBuffer::Cursor start_of_line(&*m_gap_buffer);
+    size_t bytes_written = 0u;
+
+    while (start_of_line.valid())
+    {
+        GapBuffer::Cursor cursor = start_of_line;
+        cursor.go_end_of_line(true);
+        size_t len = cursor.address() - start_of_line.address();
+        if (len > 0u)
+        {
+            if (!file.write(start_of_line.address(), len))
+            {
+                return false;
+            }
+            bytes_written += len;
+        }
+        bool moved_down = cursor.go_down(0u);
+        if (moved_down || m_eol_at_eof)
+        {
+            if (!file.write(LineEndings::spans[m_line_endings]))
+            {
+                return false;
+            }
+            bytes_written += LineEndings::spans[m_line_endings].length;
+        }
+        if (!moved_down)
+        {
+            break;
+        }
+        start_of_line = cursor;
+    }
 
     return true;
 }
diff --git a/src/core/Buffer.h b/src/core/Buffer.h
index 1eab87e..edc51e9 100644
--- a/src/core/Buffer.h
+++ b/src/core/Buffer.h
@@ -15,6 +15,7 @@ public:
 
 protected:
     bool m_eol_at_eof;
+    LineEndings::Type m_line_endings;
     std::shared_ptr<GapBuffer> m_gap_buffer;
 
     bool load_from_file(const char * filename);
diff --git a/src/core/GapBuffer.cc b/src/core/GapBuffer.cc
index d38d58f..7199d20 100644
--- a/src/core/GapBuffer.cc
+++ b/src/core/GapBuffer.cc
@@ -153,14 +153,14 @@ bool GapBuffer::Cursor::go_start_of_line()
     return moved;
 }
 
-bool GapBuffer::Cursor::go_end_of_line()
+bool GapBuffer::Cursor::go_end_of_line(bool allow_eol)
 {
     bool moved = false;
-    if (go_right(false))
+    if (go_right(allow_eol))
     {
         moved = true;
     }
-    while (go_right(false))
+    while (go_right(allow_eol))
     {
         ;
     }
@@ -230,7 +230,7 @@ bool GapBuffer::Cursor::go_up(size_t target_column)
 bool GapBuffer::Cursor::go_down(size_t target_column)
 {
     Cursor c2 = *this;
-    c2.go_end_of_line();
+    c2.go_end_of_line(true);
     if (!c2.m_iterator.check_go_forward())
     {
         return false;
diff --git a/src/core/GapBuffer.h b/src/core/GapBuffer.h
index e5f80a3..6df18a2 100644
--- a/src/core/GapBuffer.h
+++ b/src/core/GapBuffer.h
@@ -64,7 +64,7 @@ public:
         bool is_start_of_line();
         bool is_end_of_line(bool allow_eol);
         bool go_start_of_line();
-        bool go_end_of_line();
+        bool go_end_of_line(bool allow_eol);
         bool go_left();
         bool go_right(bool allow_eol);
         bool go_up(size_t target_column);
@@ -75,6 +75,7 @@ public:
         }
         uint32_t operator*() const { return *m_iterator; }
         uint8_t * address() const { return m_iterator.address(); }
+        bool valid() const { return m_iterator.valid(); }
 
     protected:
         Iterator m_iterator;