diff --git a/js/src/vm/RegExpObject.cpp b/js/src/vm/RegExpObject.cpp
index 70fc47b949..b75d4f3b32 100644
--- a/js/src/vm/RegExpObject.cpp
+++ b/js/src/vm/RegExpObject.cpp
@@ -958,17 +958,16 @@ RegExpShared::RegExpShared(JSAtom* source, RegExpFlag flags)
 {}
 
 struct RegExpShared::NamedCaptureData {
+	bool mapInited;
     // per-compartment template cache (optional; you can also skip templates entirely)
     using GroupsTemplateMap =
         GCHashMap<JSCompartment*, ReadBarriered<PlainObject*>,
                   DefaultHasher<JSCompartment*>, SystemAllocPolicy>;
     GroupsTemplateMap groupsTemplateMap;
-    bool groupsTemplateMapInited;
+    bool groupsTemplateMapInited = false;
 
     Vector<JSAtom*, 0, SystemAllocPolicy> names;
     Vector<uint32_t, 0, SystemAllocPolicy> indices;
-
-    NamedCaptureData() : groupsTemplateMapInited(false) {}
 };
 
 void
@@ -978,16 +977,14 @@ RegExpShared::traceChildren(JSTracer* trc)
     if (IsMarkingTrace(trc) && trc->runtime()->gc.isShrinkingGC())
         discardJitCode();
 
-    if (namedCaptureData_ && namedCaptureData_->groupsTemplateMapInited) {
+    if (namedCaptureData_ && namedCaptureData_->mapInited) {
 	  for (auto iter = namedCaptureData_->groupsTemplateMap.all(); !iter.empty(); iter.popFront()) {
         TraceNullableEdge(trc, &iter.front().value(), "RegExpShared groupsTemplate per-compartment");
       }
     }
 
-    if (namedCaptureData_) {
-      for (JSAtom*& atom : namedCaptureData_->names) {
-        TraceEdge(trc, &atom, "RegExpShared namedCaptureName");
-      }
+    for (auto& atom : namedCaptureNames_) {
+    TraceEdge(trc, &atom, "RegExpShared namedCaptureName");
     }
 
     TraceNullableEdge(trc, &source, "RegExpShared source");
@@ -1008,11 +1005,6 @@ RegExpShared::discardJitCode()
 void
 RegExpShared::finalize(FreeOp* fop)
 {
-	if (namedCaptureData_) {
-        js_delete(namedCaptureData_);
-        namedCaptureData_ = nullptr;
-    }
-
     for (auto& comp : compilationArray)
         js_free(comp.byteCode);
     tables.~JitCodeTables();
@@ -1409,10 +1401,10 @@ RegExpShared::getOrCreateGroupsTemplate(JSContext* cx)
 
     NamedCaptureData* data = namedCaptureData_;
 
-    if (!data->groupsTemplateMapInited) {
+    if (!data->mapInited) {
         if (!data->groupsTemplateMap.init(4))
             return nullptr;
-        data->groupsTemplateMapInited = true;
+        data->mapInited = true;
     }
 
     JSCompartment* comp = cx->compartment();
diff --git a/js/src/vm/RegExpShared.h b/js/src/vm/RegExpShared.h
index dfb80a79cd..0f617936a6 100644
--- a/js/src/vm/RegExpShared.h
+++ b/js/src/vm/RegExpShared.h
@@ -132,7 +132,13 @@ class RegExpShared : public gc::TenuredCell
     uint32_t            numNamedCaptures_;
     NamedCaptureData* namedCaptureData_;   // nullptr if none
 	public:
-    NamedCaptureData* namedCaptureData() const { return namedCaptureData_; }
+  NamedCaptureData* namedCaptureData() const { return namedCaptureData_; }
+
+bool namedCaptureDataInited_;
+
+// NEW: realm-neutral named-capture data stored on the shared regexp
+Vector<GCPtr<JSAtom*>, 0, SystemAllocPolicy> namedCaptureNames_;
+Vector<uint32_t, 0, SystemAllocPolicy> namedCaptureIndices_;
 
     RegExpCompilation  compilationArray[4];