diff --git a/src/emu/emuopts.c b/src/emu/emuopts.c
index ef73c371708..adf27712942 100644
--- a/src/emu/emuopts.c
+++ b/src/emu/emuopts.c
@@ -130,11 +130,7 @@ const options_entry mame_core_options[] =
 	{ "joystick_deadzone;joy_deadzone;jdz",      "0.3",  0,          "center deadzone range for joystick where change is ignored (0.0 center, 1.0 end)" },
 	{ "joystick_saturation;joy_saturation;jsat", "0.85", 0,          "end of axis saturation range for joystick where change is ignored (0.0 center, 1.0 end)" },
 	{ "natural;nat",				 "0",		  OPTION_BOOLEAN,	 "specifies whether to use a natural keyboard or not" },
-	#if defined(__APPLE__) && defined(__MACH__)
-	{ "uimodekey;umk",        		"ITEM_ID_INSERT",  0,    		 "specifies the key used to toggle between full and partial UI mode" },
-	#else
-	{ "uimodekey;umk",        		"ITEM_ID_SCRLOCK", 0,    		 "specifies the key used to toggle between full and partial UI mode" },
-	#endif
+	{ "uimodekey;umk",        		 "auto",  	  0,    		 	 "specifies the key used to toggle between full and partial UI mode" },
 	
 	
 	/* input autoenable options */
diff --git a/src/osd/sdl/input.c b/src/osd/sdl/input.c
index 9a5c829344a..9cfdb3e3375 100644
--- a/src/osd/sdl/input.c
+++ b/src/osd/sdl/input.c
@@ -1584,6 +1584,7 @@ void osd_customize_input_type_list(input_type_desc *typelist)
 {
 	int mameid_code ,ui_code;
 	input_type_desc *typedesc;
+	const char*  uimode;
 
 	// loop over the defaults
 	for (typedesc = typelist; typedesc != NULL; typedesc = typedesc->next)
@@ -1592,7 +1593,16 @@ void osd_customize_input_type_list(input_type_desc *typelist)
 		{
 			// configurable UI mode switch
 			case IPT_UI_TOGGLE_UI:
-				mameid_code = lookup_mame_code((const char *)options_get_string(mame_options(), SDLOPTION_UIMODEKEY));
+				uimode = (const char *)options_get_string(mame_options(), SDLOPTION_UIMODEKEY);
+				if(!strcmp(uimode,"auto")) {
+					#if defined(__APPLE__) && defined(__MACH__)
+					mameid_code = lookup_mame_code("ITEM_ID_INSERT");
+					#else
+					mameid_code = lookup_mame_code("ITEM_ID_SCRLOCK");
+					#endif
+				} else {
+					mameid_code = lookup_mame_code(uimode);
+				}
 				ui_code = INPUT_CODE(DEVICE_CLASS_KEYBOARD, 0, ITEM_CLASS_SWITCH, ITEM_MODIFIER_NONE, mameid_code);
 				input_seq_set_1(&typedesc->seq[SEQ_TYPE_STANDARD], ui_code);
 				break;