diff --git a/engine/core/script/dart_controller.cc b/engine/core/script/dart_controller.cc
index 2a05e58855233c32072551cf6226ece0e1de2935..dc7ce4c78a63d901d5517e4a7b55e984c7671a8d 100644
--- a/engine/core/script/dart_controller.cc
+++ b/engine/core/script/dart_controller.cc
@@ -204,6 +204,10 @@ static Dart_Isolate IsolateCreateCallback(const char* script_uri,
     DartApiScope apiScope;
     Builtin::SetNativeResolver(Builtin::kBuiltinLibrary);
     Builtin::SetNativeResolver(Builtin::kMojoInternalLibrary);
+
+    // Ensure the isolate has a root library.
+    Dart_LoadScript(Dart_NewStringFromCString("dart:empty"),
+                    Dart_NewStringFromCString(""), 0, 0);
   }
 
   Dart_ExitIsolate();
@@ -273,6 +277,10 @@ void DartController::CreateIsolateFor(Document* document) {
   {
     DartApiScope apiScope;
 
+    // Ensure the isolate has a root library.
+    Dart_LoadScript(Dart_NewStringFromCString("dart:empty"),
+                    Dart_NewStringFromCString(""), 0, 0);
+
     Builtin::SetNativeResolver(Builtin::kBuiltinLibrary);
     Builtin::SetNativeResolver(Builtin::kMojoInternalLibrary);
     BuiltinNatives::Init();
diff --git a/tests/dart/mirror-system-expected.txt b/tests/dart/mirror-system-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..7ef22e9a431ad0272713b71fdc8794016c8ef12f
--- /dev/null
+++ b/tests/dart/mirror-system-expected.txt
@@ -0,0 +1 @@
+PASS
diff --git a/tests/dart/mirror-system.sky b/tests/dart/mirror-system.sky
new file mode 100644
index 0000000000000000000000000000000000000000..7d751e516dca32b0e303735a73d66d78624ed697
--- /dev/null
+++ b/tests/dart/mirror-system.sky
@@ -0,0 +1,14 @@
+<script>
+import "dart:mirrors";
+import "dart:sky.internals" as internals;
+
+// Regression test for the embedder not setting up the root library.
+// Used to crash.
+
+void main() {
+  if (currentMirrorSystem().isolate.rootLibrary == null) {
+    throw "Missing root library";
+  }
+  internals.notifyTestComplete("PASS");
+}
+</script>>