diff --git a/src/debug/debug.cpp b/src/debug/debug.cpp
index 0c383c935..bdf778530 100644
--- a/src/debug/debug.cpp
+++ b/src/debug/debug.cpp
@@ -3048,6 +3048,12 @@ void DEBUG_ShutDown(Section * /*sec*/) {
 
 Bitu debugCallback;
 
+void DEBUG_ReinitCallback(void) {
+    /* this is REQUIRED after loading a custom BIOS */
+	debugCallback=CALLBACK_Allocate();
+	CALLBACK_Setup(debugCallback,DEBUG_EnableDebugger,CB_RETF,"debugger");
+}
+
 void DEBUG_Init() {
 	DOSBoxMenu::item *item;
 
diff --git a/src/gui/sdlmain.cpp b/src/gui/sdlmain.cpp
index 2dba5cf1b..22c68c517 100644
--- a/src/gui/sdlmain.cpp
+++ b/src/gui/sdlmain.cpp
@@ -7746,6 +7746,9 @@ fresh_boot:
 
                 void CALLBACK_Init();
                 CALLBACK_Init();
+
+                void DEBUG_ReinitCallback(void);
+                DEBUG_ReinitCallback();
             }
 
             DispatchVMEvent(VM_EVENT_RESET_END);