diff --git a/js/public/CompileOptions.h b/js/public/CompileOptions.h
index fa585a955936..73869ab09162 100644
--- a/js/public/CompileOptions.h
+++ b/js/public/CompileOptions.h
@@ -114,7 +114,6 @@ class JS_PUBLIC_API TransitiveCompileOptions {
   bool forceAsync = false;
   bool sourceIsLazy = false;
   bool allowHTMLComments = true;
-  bool isProbablySystemCode = false;
   bool hideScriptFromDebugger = false;
   bool bigIntEnabledOption = false;
   bool fieldsEnabledOption = false;
diff --git a/js/src/jsapi.cpp b/js/src/jsapi.cpp
index acd577388895..e7b2f7bb4253 100644
--- a/js/src/jsapi.cpp
+++ b/js/src/jsapi.cpp
@@ -3473,7 +3473,6 @@ void JS::TransitiveCompileOptions::copyPODTransitiveOptions(
   introductionLineno = rhs.introductionLineno;
   introductionOffset = rhs.introductionOffset;
   hasIntroductionInfo = rhs.hasIntroductionInfo;
-  isProbablySystemCode = rhs.isProbablySystemCode;
   hideScriptFromDebugger = rhs.hideScriptFromDebugger;
   bigIntEnabledOption = rhs.bigIntEnabledOption;
   fieldsEnabledOption = rhs.fieldsEnabledOption;
@@ -3561,7 +3560,6 @@ JS::CompileOptions::CompileOptions(JSContext* cx)
       scriptOrModuleRoot(cx) {
   strictOption = cx->options().strictMode();
   extraWarningsOption = cx->realm()->behaviors().extraWarnings(cx);
-  isProbablySystemCode = cx->realm()->isProbablySystemCode();
   werrorOption = cx->options().werror();
   if (!cx->options().asmJS()) {
     asmJSOption = AsmJSOption::Disabled;