diff --git a/runtime/lib/gl_program.rb b/runtime/lib/gl_program.rb
new file mode 100644
index 0000000..04cf827
--- /dev/null
+++ b/runtime/lib/gl_program.rb
@@ -0,0 +1,8 @@
+class GLProgram
+  # @overload initialize(*shaders, options = {})
+  #
+  # @param shaders [Array<GLShader>] Shaders to attach to the program.
+  # @param options [Hash] Optional parameters.
+  def initialize(*args)
+  end
+end
diff --git a/runtime/main.rb b/runtime/main.rb
index ea1dd16..06f8a84 100644
--- a/runtime/main.rb
+++ b/runtime/main.rb
@@ -4,6 +4,7 @@ end
 
 def load_lib_files
   require "runtime"
+  require "gl_program"
 end
 
 def main(argv)
diff --git a/src/GLProgram.cc b/src/GLProgram.cc
index 6a0c8e9..94c7dc8 100644
--- a/src/GLProgram.cc
+++ b/src/GLProgram.cc
@@ -1,4 +1,5 @@
 #include "GLProgram.h"
+#include "GLShader.h"
 #include "ruby.h"
 #include "gl3w.h"
 
@@ -21,7 +22,7 @@ static void GLProgram_free(void * ptr)
     delete program;
 }
 
-static VALUE GLProgram_new(VALUE klass)
+static VALUE GLProgram_new(int argc, VALUE * argv, VALUE klass)
 {
     GLProgram * glprogram = new GLProgram();
 
@@ -31,26 +32,29 @@ static VALUE GLProgram_new(VALUE klass)
         rb_raise(rb_eRuntimeError, "Error allocating GL program object");
     }
 
-    return Data_Wrap_Struct(klass, NULL, GLProgram_free, glprogram);
+    VALUE rv = Data_Wrap_Struct(klass, NULL, GLProgram_free, glprogram);
+    rb_obj_call_init(rv, argc, argv);
+
+    return rv;
+}
+
+static VALUE GLProgram_attach_shader(VALUE self, VALUE gl_shader)
+{
+    GLProgram * glprogram;
+    Data_Get_Struct(self, GLProgram, glprogram);
+    glAttachShader(glprogram->id, GLShader_id(gl_shader));
+
+    return Qnil;
 }
 
 void GLProgram_Init()
 {
     ruby_class = rb_define_class("GLProgram", rb_cObject);
-    rb_define_singleton_method(ruby_class, "new", (VALUE(*)(...))GLProgram_new, 0);
-    rb_define_attr(ruby_class, "id", 0, 1);
+    rb_define_singleton_method(ruby_class, "new", (VALUE(*)(...))GLProgram_new, -1);
+    rb_define_method(ruby_class, "attach_shader", (VALUE(*)(...))GLProgram_attach_shader, 1);
 }
 
 #if 0
-GLProgram & GLProgram::attach_shader(GLShaderRef shader)
-{
-    if (m_id > 0u)
-    {
-        glAttachShader(m_id, shader->get_id());
-    }
-    return *this;
-}
-
 GLProgram & GLProgram::bind_attribute(const char * attribute, GLuint index)
 {
     if (m_id > 0u)