diff --git a/components/debuggerintf/dbgintfdebuggerbase.pp b/components/debuggerintf/dbgintfdebuggerbase.pp
index b4e075d2aa..c143dff99a 100644
--- a/components/debuggerintf/dbgintfdebuggerbase.pp
+++ b/components/debuggerintf/dbgintfdebuggerbase.pp
@@ -5073,6 +5073,8 @@ begin
     FCount := FCount + AnotherRange.Count - i;
     FRangeEndAddr := AnotherRange.FRangeEndAddr;
     FLastEntryEndAddr := AnotherRange.FLastEntryEndAddr;
+    if FRangeStartAddr = 0 then
+      FRangeStartAddr := AnotherRange.FRangeStartAddr;
   end;
   debugln(DBG_DISASSEMBLER, ['INFO: TDBGDisassemblerEntryRange.Merge AFTER MERGE: ', dbgs(self) ]);
 end;