diff --git a/src/mame/drivers/trs80m3.cpp b/src/mame/drivers/trs80m3.cpp
index 9ec1ae90f05..327904a7d3a 100644
--- a/src/mame/drivers/trs80m3.cpp
+++ b/src/mame/drivers/trs80m3.cpp
@@ -74,6 +74,7 @@ trs80m4p:  floppy not working, so machine is useless
 #include "screen.h"
 #include "speaker.h"
 
+#include "formats/imd_dsk.h"
 #include "formats/trs80_dsk.h"
 #include "formats/dmk_dsk.h"
 
@@ -326,7 +327,7 @@ GFXDECODE_END
 
 void trs80m3_state::floppy_formats(format_registration &fr)
 {
-	fr.add_mfm_containers();
+	fr.add(FLOPPY_IMD_FORMAT);
 	fr.add(FLOPPY_TRS80_FORMAT);
 	fr.add(FLOPPY_DMK_FORMAT);
 }