diff --git a/src/UnitTests.Shared/MockLogger.cs b/src/UnitTests.Shared/MockLogger.cs
index c07a43b58a5..d9a72966a81 100644
--- a/src/UnitTests.Shared/MockLogger.cs
+++ b/src/UnitTests.Shared/MockLogger.cs
@@ -307,7 +307,7 @@ public void LoggerEventHandler(object sender, BuildEventArgs eventArgs)
                             bool logMessage = !(eventArgs is BuildFinishedEventArgs) || LogBuildFinished;
                             if (logMessage)
                             {
-                                string msg = eventArgs.Message;
+                                string msg = eventArgs.Message ?? $"(null message in {eventArgs.GetType().Name} event)";
                                 if (eventArgs is BuildMessageEventArgs m && m.LineNumber != 0)
                                 {
                                     msg = $"{m.File}({m.LineNumber},{m.ColumnNumber}): {msg}";