diff --git a/src/Build/Utilities/EngineFileUtilities.cs b/src/Build/Utilities/EngineFileUtilities.cs
index 82724a46b03..ec2fbc4f242 100644
--- a/src/Build/Utilities/EngineFileUtilities.cs
+++ b/src/Build/Utilities/EngineFileUtilities.cs
@@ -32,7 +32,9 @@ static EngineFileUtilities()
             }
         }
 
-        // used by test to reset regexes
+        /// <summary>
+        /// Test only: repopulate lazy wildcard regexes from the environment.
+        /// </summary>
         internal static void CaptureLazyWildcardRegexes()
         {
             s_lazyWildCardExpansionRegexes = PopulateRegexFromEnvironment();