diff --git a/src/mn_menu.c b/src/mn_menu.c
index 223b8006..4323fe2f 100644
--- a/src/mn_menu.c
+++ b/src/mn_menu.c
@@ -101,7 +101,7 @@ static int saveCharIndex; // which char we're editing
 static char saveOldString[SAVESTRINGSIZE];
 
 boolean menuactive; // The menus are up
-
+static boolean mouse_active_thermo;
 static boolean options_active;
 
 backdrop_t menu_backdrop;
@@ -2158,6 +2158,7 @@ static void M_Setup(int choice)
 void MN_ClearMenus(void)
 {
     menuactive = 0;
+    mouse_active_thermo = false;
     options_active = false;
     print_warning_about_changes = 0; // killough 8/15/98
     default_verify = 0;              // killough 10/98
@@ -2844,18 +2845,16 @@ static boolean MouseResponder(void)
         return false;
     }
 
-    static boolean active_thermo;
-
     if (M_InputActivated(input_menu_enter))
     {
-        active_thermo = true;
+        mouse_active_thermo = true;
     }
     else if (M_InputDeactivated(input_menu_enter))
     {
-        active_thermo = false;
+        mouse_active_thermo = false;
     }
 
-    if (active_thermo)
+    if (mouse_active_thermo)
     {
         int dot = mouse_state_x - (rect->x + M_THRM_STEP + video.deltaw);
         int step = M_MAX_VOL * FRACUNIT / (rect->w - M_THRM_STEP * 3);
diff --git a/src/mn_setup.c b/src/mn_setup.c
index a28bf2a5..a695885c 100644
--- a/src/mn_setup.c
+++ b/src/mn_setup.c
@@ -4474,6 +4474,13 @@ boolean MN_SetupResponder(menu_action_t action, int ch)
 
     if (action == MENU_ESCAPE || action == MENU_BACKSPACE)
     {
+        if (active_thermo && setup_cancel != -1)
+        {
+            default_t *def = active_thermo->var.def;
+            *def->location.i = setup_cancel;
+            setup_cancel = -1;
+        }
+
         SetItemOn(set_item_on);
         SetPageIndex(current_page);
 
@@ -4591,6 +4598,7 @@ boolean MN_SetupMouseResponder(int x, int y)
             }
         }
         active_thermo = NULL;
+        setup_cancel = -1;
     }
 
     if (M_InputActivated(input_menu_enter))
@@ -4623,6 +4631,11 @@ boolean MN_SetupMouseResponder(int x, int y)
         if (M_InputActivated(input_menu_enter))
         {
             active_thermo = current_item;
+
+            if (flags & S_ACTION && setup_cancel == -1)
+            {
+                setup_cancel = *def->location.i;
+            }
         }
     }