diff --git a/Makefile b/Makefile
index afc642e..4d3ba20 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 CC=g++
-CFLAGS= -c -g -Wall
 
-LDLIBS = -lgtk
+CFLAGS= -c -g -Wall $(shell pkg-config --cflags gtkmm-4.0)
+LDLIBS = $(shell pkg-config --libs gtkmm-4.0)
 
 TARGET := untap
 
@@ -15,7 +15,7 @@ OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)
 $(BUILD_DIR)/$(TARGET): $(OBJS)
 	$(CC) $(OBJS) -o $@ $(LDLIBS)
 
-$(BUILD_DIR)/%.c.o: %.cpp
+$(BUILD_DIR)/%.cpp.o: %.cpp
 	mkdir -p $(dir $@)
 	$(CC) $(CFLAGS) -c $< -o $@
 
diff --git a/build/src/helloworld.cpp.o b/build/src/helloworld.cpp.o
new file mode 100644
index 0000000..d9f6cb6
Binary files /dev/null and b/build/src/helloworld.cpp.o differ
diff --git a/build/src/main.cpp.o b/build/src/main.cpp.o
new file mode 100644
index 0000000..906a82c
Binary files /dev/null and b/build/src/main.cpp.o differ
diff --git a/build/untap b/build/untap
new file mode 100755
index 0000000..a57e87a
Binary files /dev/null and b/build/untap differ
diff --git a/src/helloworld.cpp b/src/helloworld.cpp
new file mode 100644
index 0000000..39afb9b
--- /dev/null
+++ b/src/helloworld.cpp
@@ -0,0 +1,24 @@
+#include "include/helloworld.h"
+
+#include <iostream>
+
+HelloWorld::HelloWorld()
+	: m_button("Hello world!")
+{
+	m_button.set_margin(10);
+
+	m_button.signal_clicked().connect(sigc::mem_fun(*this,
+				&HelloWorld::on_button_clicked));
+
+	set_child(m_button);
+}
+
+HelloWorld::~HelloWorld()
+{
+
+}
+
+void HelloWorld::on_button_clicked()
+{
+	std::cout << "Hello, World!" << std::endl;
+}
diff --git a/src/include/helloworld.h b/src/include/helloworld.h
new file mode 100644
index 0000000..902b6d2
--- /dev/null
+++ b/src/include/helloworld.h
@@ -0,0 +1,19 @@
+#ifndef GTKMM_EXAMPLE_HELLOWORLD_H
+#define GTKMM_EXAMPLE_HELLOWORLD_H
+
+#include <gtkmm/button.h>
+#include <gtkmm/window.h>
+
+class HelloWorld : public Gtk::Window
+{
+	public:
+		HelloWorld();
+		~HelloWorld() override;
+
+	protected:
+		void on_button_clicked();
+
+		Gtk::Button m_button;
+};
+
+#endif
diff --git a/src/main.cpp b/src/main.cpp
index e69de29..139053e 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -0,0 +1,10 @@
+#include "include/helloworld.h"
+
+#include <gtkmm/application.h>
+
+int main(int argc, char* argv[])
+{
+	auto app = Gtk::Application::create("org.gtkmm.example");
+
+	return app->make_window_and_run<HelloWorld>(argc, argv);
+}