diff --git a/scripts/src/formats.lua b/scripts/src/formats.lua
index 9e5b4bf0504..c437ef4c04d 100644
--- a/scripts/src/formats.lua
+++ b/scripts/src/formats.lua
@@ -1603,10 +1603,10 @@ end
 
 --------------------------------------------------
 --
---@src/lib/formats/rc759_dsk.h,FORMATS["RC759"] = true
+--@src/lib/formats/rc759_dsk.h,FORMATS["RC759_DSK"] = true
 --------------------------------------------------
 
-if (FORMATS["APRIDISK"]~=null  or _OPTIONS["with-tools"]) then
+if opt_tool(FORMATS, "RC759_DSK") then
 	files {
 		MAME_DIR.. "src/lib/formats/rc759_dsk.cpp",
 		MAME_DIR.. "src/lib/formats/rc759_dsk.h",
diff --git a/scripts/target/mame/mess.lua b/scripts/target/mame/mess.lua
index 88a13968032..962c0747b60 100644
--- a/scripts/target/mame/mess.lua
+++ b/scripts/target/mame/mess.lua
@@ -981,7 +981,6 @@ BUSES["X68K"] = true
 BUSES["Z29_KBD"] = true
 BUSES["Z88"] = true
 BUSES["ZORRO"] = true
-BUSES["THOMSON"] = true
 
 --------------------------------------------------
 -- specify used file formats
@@ -1112,7 +1111,7 @@ FORMATS["PPG_DSK"] = true
 FORMATS["PRIMOPTP"] = true
 FORMATS["PYLDIN_DSK"] = true
 FORMATS["QL_DSK"] = true
-FORMATS["RC759"] = true
+FORMATS["RC759_DSK"] = true
 FORMATS["RK_CAS"] = true
 FORMATS["RX50_DSK"] = true
 FORMATS["SC3000_BIT"] = true
@@ -3930,6 +3929,8 @@ files {
 	MAME_DIR .. "src/mame/drivers/thomson.cpp",
 	MAME_DIR .. "src/mame/includes/thomson.h",
 	MAME_DIR .. "src/mame/machine/thomson.cpp",
+	MAME_DIR .. "src/mame/machine/thomflop.cpp",
+	MAME_DIR .. "src/mame/machine/thomflop.h",
 	MAME_DIR .. "src/mame/video/thomson.cpp",
 }