diff --git a/README.md b/README.md
index 26c0aac..384b76c 100644
--- a/README.md
+++ b/README.md
@@ -18,9 +18,6 @@ TODO
 Current development version have some limitations
 which should be fixed in first release:
 
-* [\[issue #15\]](https://github.com/braiden-vasco/lita-tox/issues/15)
-  Only private chats are supported. Adapter will not respond to group invite
-
 * [\[issue #16\]](https://github.com/braiden-vasco/lita-tox/issues/16)
   **libtoxcore** is not included in the gem. It should be compiled manually
   to build the gem native extension successfully. Follow the instructions in
diff --git a/ext/tox/extconf.rb b/ext/tox/extconf.rb
index 6fb1c32..46cb461 100755
--- a/ext/tox/extconf.rb
+++ b/ext/tox/extconf.rb
@@ -8,6 +8,7 @@ LIBTOXCORE = 'toxcore'
 
 have_header 'time.h' and
 have_header 'tox/tox.h' and
+have_header 'tox/tox_old.h' and
 
 have_func 'sprintf' and
 have_func 'sscanf' and
@@ -27,5 +28,10 @@ have_library LIBTOXCORE, 'tox_friend_add_norequest' and
 have_library LIBTOXCORE, 'tox_friend_send_message' and
 have_library LIBTOXCORE, 'tox_callback_friend_request' and
 have_library LIBTOXCORE, 'tox_callback_friend_message' and
+have_library LIBTOXCORE, 'tox_join_groupchat' and
+have_library LIBTOXCORE, 'tox_group_message_send' and
+have_library LIBTOXCORE, 'tox_callback_group_invite' and
+have_library LIBTOXCORE, 'tox_callback_group_message' and
+have_library LIBTOXCORE, 'tox_group_peernumber_is_ours' and
 
 create_makefile "#{NAME}/#{NAME}" or exit(1)
diff --git a/ext/tox/tox.c b/ext/tox/tox.c
index d6c8343..24e0dca 100644
--- a/ext/tox/tox.c
+++ b/ext/tox/tox.c
@@ -40,6 +40,9 @@ static VALUE cTox_kill(VALUE self);
 static VALUE cTox_loop(VALUE self);
 static VALUE cTox_friend_add_norequest(VALUE self, VALUE key);
 static VALUE cTox_friend_send_message(VALUE self, VALUE friend_number, VALUE text);
+static VALUE cTox_join_groupchat(VALUE self, VALUE friend_number, VALUE data);
+static VALUE cTox_group_message_send(VALUE self, VALUE group_number, VALUE text);
+static VALUE cTox_group_peernumber_is_ours(VALUE self, VALUE group_number, VALUE peer_number);
 
 static void on_friend_request(
   Tox *tox,
@@ -56,6 +59,24 @@ static void on_friend_message(
   size_t length,
   VALUE self);
 
+static void on_group_invite(
+    Tox *tox,
+    int32_t friend_number,
+    uint8_t type,
+    const uint8_t *data,
+    uint16_t length,
+    VALUE self
+  );
+
+static void on_group_message(
+    Tox *tox,
+    int group_number,
+    int peer_number,
+    const uint8_t *text,
+    uint16_t length,
+    VALUE self
+  );
+
 typedef struct Tox_Options cTox_cOptions_;
 
 static VALUE cTox_cOptions;
@@ -80,6 +101,9 @@ void Init_tox()
   rb_define_method(cTox, "loop", cTox_loop, 0);
   rb_define_method(cTox, "friend_add_norequest", cTox_friend_add_norequest, 1);
   rb_define_method(cTox, "friend_send_message", cTox_friend_send_message, 2);
+  rb_define_method(cTox, "join_groupchat", cTox_join_groupchat, 2);
+  rb_define_method(cTox, "group_message_send", cTox_group_message_send, 2);
+  rb_define_method(cTox, "group_peernumber_is_ours", cTox_group_peernumber_is_ours, 2);
 
   cTox_cOptions = rb_define_class_under(cTox, "Options", rb_cObject);
   rb_define_alloc_func(cTox_cOptions, cTox_cOptions_alloc);
@@ -138,6 +162,14 @@ VALUE cTox_initialize_with(const VALUE self, const VALUE options)
 
   tox_callback_friend_request(tox->tox, (tox_friend_request_cb*)on_friend_request, (void*)self);
   tox_callback_friend_message(tox->tox, (tox_friend_message_cb*)on_friend_message, (void*)self);
+  tox_callback_group_invite(
+    tox->tox,
+    (void (*)(struct Tox *, int32_t, uint8_t, const uint8_t *, uint16_t, void *))on_group_invite,
+    (void*)self);
+  tox_callback_group_message(
+    tox->tox,
+    (void (*)(struct Tox *, int, int, const uint8_t *, uint16_t, void *))on_group_message,
+    (void*)self);
 
   return self;
 }
@@ -281,6 +313,65 @@ VALUE cTox_friend_send_message(const VALUE self, const VALUE friend_number, cons
   ));
 }
 
+VALUE cTox_join_groupchat(const VALUE self, const VALUE friend_number, const VALUE data)
+{
+  cTox_ *tox;
+
+  // Don't know yet how to check for integers
+  // Check_Type(friend_number, T_INTEGER);
+  Check_Type(data, T_STRING);
+
+  Data_Get_Struct(self, cTox_, tox);
+
+  return INT2FIX(tox_join_groupchat(
+    tox->tox,
+    NUM2LONG(friend_number),
+    (uint8_t*)RSTRING_PTR(data),
+    RSTRING_LEN(data)
+  ));
+}
+
+VALUE cTox_group_message_send(const VALUE self, const VALUE group_number, const VALUE text)
+{
+  cTox_ *tox;
+
+  // Don't know yet how to check for integers
+  // Check_Type(group_number, T_INTEGER);
+  Check_Type(text, T_STRING);
+
+  Data_Get_Struct(self, cTox_, tox);
+
+  return INT2FIX(tox_group_message_send(
+    tox->tox,
+    NUM2LONG(group_number),
+    (uint8_t*)RSTRING_PTR(text),
+    RSTRING_LEN(text)
+  ));
+}
+
+VALUE cTox_group_peernumber_is_ours(
+  const VALUE self,
+  const VALUE group_number,
+  const VALUE peer_number)
+{
+  cTox_ *tox;
+
+  // Don't know yet how to check for integers
+  // Check_Type(group_number, T_INTEGER);
+  // Check_Type(peer_number, T_INTEGER);
+
+  Data_Get_Struct(self, cTox_, tox);
+
+  if (tox_group_peernumber_is_ours(
+    tox->tox,
+    NUM2INT(group_number),
+    NUM2INT(peer_number))
+  )
+    return Qtrue;
+  else
+    return Qfalse;
+}
+
 void on_friend_request(
   Tox *const tox,
   const uint8_t *const key,
@@ -327,6 +418,51 @@ void on_friend_message(
     );
 }
 
+static void on_group_invite(
+    Tox *const tox,
+    const int32_t friend_number,
+    const uint8_t type,
+    const uint8_t *const data,
+    const uint16_t length,
+    const VALUE self)
+{
+  VALUE rb_on_group_invite;
+
+  rb_on_group_invite = rb_iv_get(self, "@on_group_invite");
+
+  if (Qnil != rb_on_group_invite)
+    rb_funcall(
+      rb_on_group_invite,
+      rb_intern("call"),
+      2,
+      LONG2FIX(friend_number),
+      rb_str_new((char*)data, length)
+    );
+}
+
+static void on_group_message(
+    Tox *const tox,
+    const int group_number,
+    const int peer_number,
+    const uint8_t *const text,
+    const uint16_t length,
+    const VALUE self)
+{
+  VALUE rb_on_group_message;
+
+  rb_on_group_message = rb_iv_get(self, "@on_group_message");
+
+  if (Qnil != rb_on_group_message)
+    rb_funcall(
+      rb_on_group_message,
+      rb_intern("call"),
+      3,
+      LONG2FIX(group_number),
+      LONG2FIX(peer_number),
+      rb_str_new((char*)text, length)
+    );
+}
+
 /******************************************************************************
  * Tox::Options
  ******************************************************************************/
diff --git a/lib/lita/adapters/tox.rb b/lib/lita/adapters/tox.rb
index 1b3f998..deffaeb 100644
--- a/lib/lita/adapters/tox.rb
+++ b/lib/lita/adapters/tox.rb
@@ -41,6 +41,20 @@ module Lita
           message.command!
           robot.receive(message)
         end
+
+        @tox.on_group_invite do |friend_number, data|
+          @tox.join_groupchat(friend_number, data)
+        end
+
+        @tox.on_group_message do |group_number, peer_number, text|
+          unless @tox.group_peernumber_is_ours(group_number, peer_number)
+            user = User.new(-1 - peer_number) # TODO
+            source = Source.new(user: user, room: group_number)
+            message = Message.new(robot, text, source)
+
+            robot.receive(message)
+          end
+        end
       end
 
       def run
@@ -59,7 +73,11 @@ module Lita
 
       def send_messages(target, messages)
         messages.reject(&:empty?).each do |message|
-          @tox.friend_send_message(target.user.id.to_i, message)
+          if target.user.id.to_i >= 0
+            @tox.friend_send_message(target.user.id.to_i, message)
+          else
+            @tox.group_message_send(target.room.to_i, message)
+          end
         end
       end
     end
diff --git a/lib/tox.rb b/lib/tox.rb
index ccab134..f390ecf 100644
--- a/lib/tox.rb
+++ b/lib/tox.rb
@@ -50,4 +50,12 @@ class Tox
   def on_friend_message(&block)
     @on_friend_message = block
   end
+
+  def on_group_invite(&block)
+    @on_group_invite = block
+  end
+
+  def on_group_message(&block)
+    @on_group_message = block
+  end
 end