diff --git a/src/Type.h b/src/Type.h
index f8c9e385f7..e7dc3c52a2 100644
--- a/src/Type.h
+++ b/src/Type.h
@@ -618,11 +618,16 @@ public:
 
     const detail::AttrPtr& GetAttr(detail::AttrTag a) const { return attrs ? attrs->Find(a) : detail::Attr::nil; }
 
+    const detail::Location* GetLocationInfo() const { return &loc; }
+
     void DescribeReST(ODesc* d, bool roles_only = false) const;
 
     TypePtr type;
     detail::AttributesPtr attrs;
     const char* id = nullptr;
+
+private:
+    detail::Location loc = detail::GetCurrentLocation();
 };
 
 using type_decl_list = PList<TypeDecl>;
diff --git a/src/script_opt/CPP/InitsInfo.cc b/src/script_opt/CPP/InitsInfo.cc
index b9a5551cd9..122b37b9b2 100644
--- a/src/script_opt/CPP/InitsInfo.cc
+++ b/src/script_opt/CPP/InitsInfo.cc
@@ -544,7 +544,8 @@ void FuncTypeInfo::AddInitializerVals(std::vector<std::string>& ivs) const {
     ivs.emplace_back(Fmt(static_cast<int>(expressionless_return_okay)));
 }
 
-RecordTypeInfo::RecordTypeInfo(CPPCompile* _c, TypePtr _t) : AbstractTypeInfo(_c, std::move(_t)) {
+RecordTypeInfo::RecordTypeInfo(CPPCompile* _c, TypePtr _t, int _addl_fields)
+    : AbstractTypeInfo(_c, std::move(_t)), addl_fields(_addl_fields) {
     // Note, we leave init_cohort at 0 because the skeleton of this type
     // is built in the first cohort.
     auto r = t->AsRecordType()->Types();
@@ -574,6 +575,7 @@ RecordTypeInfo::RecordTypeInfo(CPPCompile* _c, TypePtr _t) : AbstractTypeInfo(_c
 
 void RecordTypeInfo::AddInitializerVals(std::vector<std::string>& ivs) const {
     ivs.emplace_back(Fmt(c->TrackString(t->GetName())));
+    ivs.emplace_back(Fmt(addl_fields));
 
     auto n = field_names.size();
 
diff --git a/src/script_opt/CPP/InitsInfo.h b/src/script_opt/CPP/InitsInfo.h
index f900b8273c..b7e58b63d1 100644
--- a/src/script_opt/CPP/InitsInfo.h
+++ b/src/script_opt/CPP/InitsInfo.h
@@ -644,11 +644,15 @@ private:
 
 class RecordTypeInfo : public AbstractTypeInfo {
 public:
-    RecordTypeInfo(CPPCompile* c, TypePtr _t);
+    RecordTypeInfo(CPPCompile* c, TypePtr _t, int _addl_fields);
 
     void AddInitializerVals(std::vector<std::string>& ivs) const override;
 
 private:
+    // If non-zero, where additional fields begin. Only used for standalone
+    // compilation.
+    int addl_fields;
+
     std::vector<std::string> field_names;
     std::vector<TypePtr> field_types;
     std::vector<int> field_attrs;
diff --git a/src/script_opt/CPP/RuntimeInits.cc b/src/script_opt/CPP/RuntimeInits.cc
index 37249be638..b7f28a7403 100644
--- a/src/script_opt/CPP/RuntimeInits.cc
+++ b/src/script_opt/CPP/RuntimeInits.cc
@@ -383,11 +383,18 @@ TypePtr CPP_TypeInits::BuildRecordType(InitsManager* im, ValElemVec& init_vals,
     auto r = cast_intrusive<RecordType>(inits_vec[offset]);
     ASSERT(r);
 
-    if ( r->NumFields() == 0 ) {
+    auto addl_fields = init_vals[2];
+
+    if ( addl_fields > 0 || r->NumFields() == 0 ) {
+        // We shouldn't be adding fields if the record doesn't have any
+        // existing fields - that would reflect an initialization botch.
+        if ( addl_fields > 0 && r->NumFields() == 0 )
+            reporter->InternalError("record unexpectedly empty when adding fields");
+
         type_decl_list tl;
 
         auto n = init_vals.size();
-        auto i = 2U;
+        auto i = 3U + addl_fields * 3;
 
         while ( i < n ) {
             auto s = im->Strings(init_vals[i++]);
diff --git a/src/script_opt/CPP/Types.cc b/src/script_opt/CPP/Types.cc
index 37215c0d62..42f4c7ec82 100644
--- a/src/script_opt/CPP/Types.cc
+++ b/src/script_opt/CPP/Types.cc
@@ -189,9 +189,43 @@ shared_ptr<CPP_InitInfo> CPPCompile::RegisterType(const TypePtr& tp) {
 
     processed_types[t] = nullptr;
 
+    // When doing standalone compilation, if the type is a record *and*
+    // (1) it's not one that we're fully generating (i.e., it's not solely
+    // defined in the scripts that we're compiling-to-standalone), and (2) the
+    // scripts we're compiling extend the record using "redef += record ...",
+    // then we need to track the offset where those record extensions start,
+    // so that when initializing the standalone code, we can add in those
+    // record fields.
+    //
+    // If any of those conditions don't hold, then this variable will remain 0.
+    int addl_fields = 0;
+
+    bool type_init_needed = standalone && obj_matches_opt_files(tp);
+
+    if ( standalone && ! type_init_needed ) {
+        if ( tp->Tag() == TYPE_RECORD ) {
+            auto tr = tp->AsRecordType();
+            for ( auto i = tr->NumOrigFields(); i < tr->NumFields(); ++i ) {
+                auto fd = tr->FieldDecl(i);
+                if ( filename_matches_opt_files(fd->GetLocationInfo()->filename) ) {
+                    if ( addl_fields == 0 )
+                        addl_fields = i;
+                }
+                else if ( addl_fields > 0 )
+                    reporter->FatalError(
+                        "can't compile standalone-C++ with field \"%s\" in record \"%s\" added after those introduced "
+                        "by compiled script",
+                        fd->id, t->GetName().c_str());
+            }
+
+            if ( addl_fields > 0 )
+                type_init_needed = true;
+        }
+    }
+
     shared_ptr<CPP_InitInfo> gi;
 
-    if ( (standalone && obj_matches_opt_files(tp)) || t->GetName().empty() ) {
+    if ( type_init_needed || t->GetName().empty() ) {
         switch ( t->Tag() ) {
             case TYPE_ADDR:
             case TYPE_ANY:
@@ -221,7 +255,7 @@ shared_ptr<CPP_InitInfo> CPPCompile::RegisterType(const TypePtr& tp) {
 
             case TYPE_TABLE: gi = make_shared<TableTypeInfo>(this, tp); break;
 
-            case TYPE_RECORD: gi = make_shared<RecordTypeInfo>(this, tp); break;
+            case TYPE_RECORD: gi = make_shared<RecordTypeInfo>(this, tp, addl_fields); break;
 
             case TYPE_FUNC: gi = make_shared<FuncTypeInfo>(this, tp); break;
 
diff --git a/src/script_opt/ScriptOpt.cc b/src/script_opt/ScriptOpt.cc
index 2175570085..f160d1e963 100644
--- a/src/script_opt/ScriptOpt.cc
+++ b/src/script_opt/ScriptOpt.cc
@@ -125,13 +125,13 @@ bool should_analyze(const ScriptFuncPtr& f, const StmtPtr& body) {
     return false;
 }
 
-bool obj_matches_opt_files(const Obj* obj) {
+bool filename_matches_opt_files(const char* filename) {
     auto& ofiles = analysis_options.only_files;
 
     if ( ofiles.empty() )
         return false;
 
-    auto fin = util::detail::normalize_path(obj->GetLocationInfo()->filename);
+    auto fin = util::detail::normalize_path(filename);
 
     for ( auto& o : ofiles )
         if ( std::regex_match(fin, o) )
@@ -140,6 +140,8 @@ bool obj_matches_opt_files(const Obj* obj) {
     return false;
 }
 
+bool obj_matches_opt_files(const Obj* obj) { return filename_matches_opt_files(obj->GetLocationInfo()->filename); }
+
 static bool optimize_AST(ScriptFuncPtr f, std::shared_ptr<ProfileFunc>& pf, std::shared_ptr<Reducer>& rc,
                          ScopePtr scope, StmtPtr& body) {
     pf = std::make_shared<ProfileFunc>(f.get(), body, true);
diff --git a/src/script_opt/ScriptOpt.h b/src/script_opt/ScriptOpt.h
index 028a93ea54..f36888272e 100644
--- a/src/script_opt/ScriptOpt.h
+++ b/src/script_opt/ScriptOpt.h
@@ -254,8 +254,9 @@ extern void add_file_analysis_pattern(AnalyOpt& opts, const char* pat);
 // it should be skipped.
 extern bool should_analyze(const ScriptFuncPtr& f, const StmtPtr& body);
 
-// True if the given object's location matches one specified by
+// True if the given filename or object location matches one specified by
 // --optimize-files=...
+extern bool filename_matches_opt_files(const char* filename);
 extern bool obj_matches_opt_files(const Obj* obj);
 inline bool obj_matches_opt_files(const ObjPtr& obj) { return obj_matches_opt_files(obj.get()); }