diff --git a/src/devices/bus/ieee488/hp9122c.cpp b/src/devices/bus/ieee488/hp9122c.cpp
index 0c6788c213d..2a001d2a4d0 100644
--- a/src/devices/bus/ieee488/hp9122c.cpp
+++ b/src/devices/bus/ieee488/hp9122c.cpp
@@ -393,7 +393,7 @@ void hp9122c_device::device_add_mconfig(machine_config &config)
 	m_i8291a->int_write().set(FUNC(hp9122c_device::i8291a_int_w));
 	m_i8291a->dreq_write().set(FUNC(hp9122c_device::i8291a_dreq_w));
 
-	FLOPPY_CONNECTOR(config, "floppy0" , hp9122c_floppies , "35hd" , nullptr, true).enable_sound(true);
-	FLOPPY_CONNECTOR(config, "floppy1" , hp9122c_floppies , "35hd" , nullptr, true).enable_sound(true);
+	FLOPPY_CONNECTOR(config, "floppy0" , hp9122c_floppies , "35hd" , floppy_image_device::default_mfm_floppy_formats, true).enable_sound(true);
+	FLOPPY_CONNECTOR(config, "floppy1" , hp9122c_floppies , "35hd" , floppy_image_device::default_mfm_floppy_formats, true).enable_sound(true);
 	config.set_default_layout(layout_hp9122c);
 }