diff --git a/src/mess/drivers/altos5.c b/src/mess/drivers/altos5.c
index 6f852ed583d..e9bf30400c5 100644
--- a/src/mess/drivers/altos5.c
+++ b/src/mess/drivers/altos5.c
@@ -327,7 +327,7 @@ WRITE8_MEMBER( altos5_state::port09_w )
 }
 
 static SLOT_INTERFACE_START( altos5_floppies )
-	SLOT_INTERFACE( "525dd", FLOPPY_525_DD )
+	SLOT_INTERFACE( "525qd", FLOPPY_525_QD )
 SLOT_INTERFACE_END
 
 WRITE_LINE_MEMBER( altos5_state::fdc_intrq_w )
@@ -433,8 +433,8 @@ static MACHINE_CONFIG_START( altos5, altos5_state )
 	MCFG_FD1797x_ADD("fdc", XTAL_8MHz / 8)
 	MCFG_WD_FDC_INTRQ_CALLBACK(WRITELINE(altos5_state, fdc_intrq_w))
 	MCFG_WD_FDC_DRQ_CALLBACK(DEVWRITELINE("z80dma", z80dma_device, rdy_w))
-	MCFG_FLOPPY_DRIVE_ADD("fdc:0", altos5_floppies, "525dd", floppy_image_device::default_floppy_formats)
-	MCFG_FLOPPY_DRIVE_ADD("fdc:1", altos5_floppies, "525dd", floppy_image_device::default_floppy_formats)
+	MCFG_FLOPPY_DRIVE_ADD("fdc:0", altos5_floppies, "525qd", floppy_image_device::default_floppy_formats)
+	MCFG_FLOPPY_DRIVE_ADD("fdc:1", altos5_floppies, "525qd", floppy_image_device::default_floppy_formats)
 MACHINE_CONFIG_END