diff --git a/compiler/src/main/pascal/Blaise.pas b/compiler/src/main/pascal/Blaise.pas
index 5f6a555..171e0ee 100644
--- a/compiler/src/main/pascal/Blaise.pas
+++ b/compiler/src/main/pascal/Blaise.pas
@@ -941,6 +941,7 @@ begin
       else
         CG := TCodeGenQBE.Create();
       CG.SetDebugMode(DebugMode);
+      CG.SetOpdfMode(OPDFEnabled);
       if IsUnitMode then
       begin
         { Unit-as-top-level: emit just the unit's bodies, no program wrapping, no @main. }
diff --git a/compiler/src/main/pascal/blaise.codegen.native.pas b/compiler/src/main/pascal/blaise.codegen.native.pas
index 64afa5e..80aed06 100644
--- a/compiler/src/main/pascal/blaise.codegen.native.pas
+++ b/compiler/src/main/pascal/blaise.codegen.native.pas
@@ -57,6 +57,7 @@ type
     procedure GenerateUnit(AUnit: TUnit);
     procedure SetSymbolTable(ASymTable: TSymbolTable);
     procedure SetDebugMode(AEnabled: Boolean);
+    procedure SetOpdfMode(AEnabled: Boolean);
     procedure AppendUnit(AUnit: TUnit);
     procedure AppendProgram(AProg: TProgram);
     function  GetOutput: string;
@@ -125,6 +126,13 @@ begin
   FDebugMode := AEnabled;
 end;
 
+procedure TCodeGenNative.SetOpdfMode(AEnabled: Boolean);
+begin
+  { No-op: OPDF debug info is not yet wired through the native backend.  Its
+    own vtables are already emitted .globl (see EmitClassSection), so there is
+    nothing to toggle here. }
+end;
+
 procedure TCodeGenNative.Generate(AProg: TProgram);
 begin
   Self.EnsureBackend();
diff --git a/compiler/src/main/pascal/uCodeGen.pas b/compiler/src/main/pascal/uCodeGen.pas
index 676a83d..39ea269 100644
--- a/compiler/src/main/pascal/uCodeGen.pas
+++ b/compiler/src/main/pascal/uCodeGen.pas
@@ -44,6 +44,13 @@ type
     { Enable backend debug/leak-tracking behaviour. }
     procedure SetDebugMode(AEnabled: Boolean);
 
+    { Enable OPDF-debug code shaping.  When on, the backend emits class vtables
+      as exported (global) symbols so the separately-assembled .opdf section can
+      reference them across object files (the OPDF class record stores each
+      class's VMTAddress for runtime dynamic-type resolution).  Off by default,
+      so normal builds are byte-for-byte unchanged. }
+    procedure SetOpdfMode(AEnabled: Boolean);
+
     { Multi-unit compilation: append unit IR to existing output without
       resetting the output buffer or string-literal table. }
     procedure AppendUnit(AUnit: TUnit);
diff --git a/compiler/src/main/pascal/uCodeGenQBE.pas b/compiler/src/main/pascal/uCodeGenQBE.pas
index 336a441..d961ab2 100644
--- a/compiler/src/main/pascal/uCodeGenQBE.pas
+++ b/compiler/src/main/pascal/uCodeGenQBE.pas
@@ -154,6 +154,9 @@ type
     procedure EmitMainHeader;
     procedure EmitMainFooter;
     procedure EmitTypeInfoDefs(AProg: TProgram);
+    { 'export data ' when OPDF-debug mode is on (so the .opdf section can
+      reference the vtable across object files), else plain 'data '. }
+    function  VTableDataPrefix: string;
     procedure EmitVTableDefs(AProg: TProgram);
     procedure EmitMethodDefs(AProg: TProgram);
     procedure EmitInterfaceDefs(AProg: TProgram);
@@ -373,6 +376,7 @@ type
   public
     FDebugMode: Boolean;
     FExportAll: Boolean;
+    FOpdfMode:  Boolean;
     constructor Create;
     destructor Destroy; override;
     procedure Generate(AProg: TProgram);
@@ -386,6 +390,7 @@ type
       the units contain class type definitions.  Prog.SymbolTable is correct. }
     procedure SetSymbolTable(ASymTable: TSymbolTable);
     procedure SetDebugMode(AEnabled: Boolean);
+    procedure SetOpdfMode(AEnabled: Boolean);
     procedure SetExportAll(AEnabled: Boolean);
     procedure AppendUnit(AUnit: TUnit);
     { Append program IR to existing output (companion to AppendUnit).
@@ -6098,8 +6103,11 @@ begin
     if (TDesc = nil) or not (TDesc is TRecordTypeDesc) then Continue;
     RT := TRecordTypeDesc(TDesc);
     if not RT.HasVTable() then Continue;
-    { TypeInfo pointer is always the first vtable entry }
-    Line := 'data $vtable_' + ClassSymName(TD.Name) +
+    { TypeInfo pointer is always the first vtable entry.  In OPDF-debug mode the
+      vtable is exported so the separately-assembled .opdf section can reference
+      it (the OPDF class record stores each class's VMTAddress); otherwise it
+      stays a local symbol, keeping non-debug output unchanged. }
+    Line := VTableDataPrefix() + '$vtable_' + ClassSymName(TD.Name) +
             ' = { l $typeinfo_' + ClassSymName(TD.Name);
     for S := 0 to RT.VTableCount() - 1 do
     begin
@@ -6123,7 +6131,7 @@ begin
     RT    := TRecordTypeDesc(GI.TypeDesc);
     if not RT.HasVTable() then Continue;
     MName := QBEMangle(GI.TypeName);
-    Line  := 'data $vtable_' + MName + ' = { l $typeinfo_' + MName;
+    Line  := VTableDataPrefix() + '$vtable_' + MName + ' = { l $typeinfo_' + MName;
     for S := 0 to RT.VTableCount() - 1 do
     begin
       E := RT.VTableEntryAt(S);
@@ -11191,6 +11199,19 @@ begin
   FDebugMode := AEnabled;
 end;
 
+procedure TCodeGenQBE.SetOpdfMode(AEnabled: Boolean);
+begin
+  FOpdfMode := AEnabled;
+end;
+
+function TCodeGenQBE.VTableDataPrefix: string;
+begin
+  if FOpdfMode then
+    Result := 'export data '
+  else
+    Result := 'data ';
+end;
+
 procedure TCodeGenQBE.SetExportAll(AEnabled: Boolean);
 begin
   FExportAll := AEnabled;