diff --git a/src/cpu/core_full/op.h b/src/cpu/core_full/op.h
index 62f285d7..e3ebfd88 100644
--- a/src/cpu/core_full/op.h
+++ b/src/cpu/core_full/op.h
@@ -341,7 +341,7 @@ switch (inst.code.op) {
 	case O_INT:
 		SaveIP();
 #if C_DEBUG
-		if ((inst.entry==0xcc) && DEBUG_Breakpoint()) return 1;
+		if (((inst.entry & 0xFF)==0xcc) && DEBUG_Breakpoint()) return 1;
 		else if (DEBUG_IntBreakpoint(inst.op1.b)) return 1;
 #endif
 		Interrupt(inst.op1.b);