diff --git a/dosbox-0.74/src/debug/debug.cpp b/dosbox-0.74/src/debug/debug.cpp
index 118bb84..547f885 100644
--- a/dosbox-0.74/src/debug/debug.cpp
+++ b/dosbox-0.74/src/debug/debug.cpp
@@ -78,11 +78,11 @@ Bit32u GetHexValue(char* str, char*& hex);
 
 class DebugPageHandler : public PageHandler {
 public:
-	Bitu readb(PhysPt /*addr*/) {
+	Bitu readb(PhysPt /*addr*/) { return -1;
 	}
-	Bitu readw(PhysPt /*addr*/) {
+	Bitu readw(PhysPt /*addr*/) { return -1;
 	}
-	Bitu readd(PhysPt /*addr*/) {
+	Bitu readd(PhysPt /*addr*/) { return -1;
 	}
 	void writeb(PhysPt /*addr*/,Bitu /*val*/) {
 	}