diff --git a/src/Serilog.Sinks.MongoDB/Sinks/MongoDB/MongoDBJsonFormatter.cs b/src/Serilog.Sinks.MongoDB/Sinks/MongoDB/MongoDBJsonFormatter.cs
index 619e86a..b09a4b6 100644
--- a/src/Serilog.Sinks.MongoDB/Sinks/MongoDB/MongoDBJsonFormatter.cs
+++ b/src/Serilog.Sinks.MongoDB/Sinks/MongoDB/MongoDBJsonFormatter.cs
@@ -84,7 +84,7 @@ protected override void WriteJsonProperty(
         }
         else
         {
-            base.WriteJsonProperty(name, value, ref precedingDelimiter, output);
+            base.WriteJsonProperty(name, value!, ref precedingDelimiter, output);
         }
     }