diff --git a/src/mess/drivers/gba.c b/src/mess/drivers/gba.c
index 390023eb56a..e4d96f5526b 100644
--- a/src/mess/drivers/gba.c
+++ b/src/mess/drivers/gba.c
@@ -916,7 +916,7 @@ READ32_MEMBER(gba_state::gba_io_r)
 		case 0x0130/4:
 			if( (mem_mask) & 0x0000ffff )   // KEYINPUT
 			{
-				retval = ioport("IN0")->read();
+				retval = m_io_in0->read();
 			}
 			else if( (mem_mask) & 0xffff0000 )
 			{
diff --git a/src/mess/includes/gba.h b/src/mess/includes/gba.h
index e76da8260a9..31d0e7ce45b 100644
--- a/src/mess/includes/gba.h
+++ b/src/mess/includes/gba.h
@@ -147,7 +147,9 @@ public:
 		m_radac(*this, "direct_a_right"),
 		m_lbdac(*this, "direct_b_left"),
 		m_rbdac(*this, "direct_b_right"),
-		m_gbsound(*this, "custom"){ }
+		m_gbsound(*this, "custom"),
+		m_io_in0(*this, "IN0")
+	{ }
 
 	required_device<cpu_device> m_maincpu;
 	required_shared_ptr<UINT32> m_gba_pram;
@@ -279,6 +281,9 @@ public:
 	TIMER_CALLBACK_MEMBER(perform_scan);
 	void gba_machine_stop();
 	DECLARE_DEVICE_IMAGE_LOAD_MEMBER(gba_cart);
+
+protected:
+	required_ioport m_io_in0;
 };
 
 /*----------- defined in video/gba.c -----------*/