diff --git a/runtime/dart_isolate.cc b/runtime/dart_isolate.cc
index 3aab39c867712..244f5969dea61 100644
--- a/runtime/dart_isolate.cc
+++ b/runtime/dart_isolate.cc
@@ -720,7 +720,8 @@ bool EndsWith(const std::string& str, const std::string& ending) {
 }
 
 Dart_Handle FindDartPluginRegistrantLibrary() {
-  // TODO(): Instead of finding this, it could be passed down from the tool.
+  // TODO(99308): Instead of finding this, it could be passed down from the
+  // tool.
   Dart_Handle libraries = Dart_GetLoadedLibraries();
   intptr_t length = 0;
   Dart_ListLength(libraries, &length);
diff --git a/testing/run_tests.py b/testing/run_tests.py
index 5393c519c745c..9b88e14b1e848 100755
--- a/testing/run_tests.py
+++ b/testing/run_tests.py
@@ -202,6 +202,10 @@ def RunCCTests(build_dir, filter, coverage, capture_core_dump):
 
   RunEngineExecutable(build_dir, 'tonic_unittests', filter, shuffle_flags, coverage=coverage)
 
+  RunEngineExecutable(build_dir, 'no_dart_plugin_registrant_unittests', filter, shuffle_flags, coverage=coverage)
+
+  RunEngineExecutable(build_dir, 'dart_plugin_registrant_unittests', filter, shuffle_flags, coverage=coverage)
+
   if not IsWindows():
     # https://github.com/flutter/flutter/issues/36295
     RunEngineExecutable(build_dir, 'shell_unittests', filter, shuffle_flags, coverage=coverage)