diff --git a/src/mame/drivers/igspoker.c b/src/mame/drivers/igspoker.c
index 194fb513e1c..f692235f18d 100644
--- a/src/mame/drivers/igspoker.c
+++ b/src/mame/drivers/igspoker.c
@@ -97,7 +97,7 @@ public:
 	tilemap_t *m_fg_tilemap;
 	tilemap_t *m_bg_tilemap;
 	UINT8 m_out[3];
-	size_t m_protection_res;
+	UINT8 m_protection_res;
 
 	DECLARE_READ8_MEMBER(igs_irqack_r);
 	DECLARE_WRITE8_MEMBER(igs_irqack_w);
@@ -300,7 +300,7 @@ WRITE8_MEMBER(igspoker_state::igs_lamps_w)
 READ8_MEMBER(igspoker_state::custom_io_r)
 {
 #if VERBOSE
-	logerror("PC %06X: Protection read %02x\n",space.device().safe_pc(), (int) m_protection_res);
+	logerror("PC %06X: Protection read %02x\n",space.device().safe_pc(), m_protection_res);
 #endif
 	return m_protection_res;
 }
diff --git a/src/mame/drivers/namcos21.c b/src/mame/drivers/namcos21.c
index 7117b7074f3..430ca916f28 100644
--- a/src/mame/drivers/namcos21.c
+++ b/src/mame/drivers/namcos21.c
@@ -536,7 +536,7 @@ UINT16 namcos21_state::read_word_from_slave_input()
 	return data;
 }
 
-size_t namcos21_state::get_input_bytes_advertised_for_slave()
+UINT16 namcos21_state::get_input_bytes_advertised_for_slave()
 {
 	if( m_mpDspState->slaveBytesAdvertised < m_mpDspState->slaveBytesAvailable )
 	{
diff --git a/src/mame/includes/namcos21.h b/src/mame/includes/namcos21.h
index 08890acdf6d..2117219ae66 100644
--- a/src/mame/includes/namcos21.h
+++ b/src/mame/includes/namcos21.h
@@ -172,7 +172,7 @@ public:
 	void transmit_word_to_slave(UINT16 data);
 	void transfer_dsp_data();
 	UINT16 read_word_from_slave_input();
-	size_t get_input_bytes_advertised_for_slave();
+	UINT16 get_input_bytes_advertised_for_slave();
 	int init_dsp();
 	void render_slave_output(UINT16 data);
 	void winrun_flush_poly();