diff --git a/docs/Conditional-processing-and-comment-syntax.md b/docs/Conditional-processing-and-comment-syntax.md
index 7d5bdab847a..33bf6966b12 100644
--- a/docs/Conditional-processing-and-comment-syntax.md
+++ b/docs/Conditional-processing-and-comment-syntax.md
@@ -393,7 +393,7 @@ In this sample, conditional expression is inside the comment `<!--` and `-->` in
 
 #### File Extensions
 
-`.*proj`, `.proj.user`, `.msbuild`, `.targets`, `.props`
+`.*proj`, `.proj.user`, `.msbuild`, `.targets`, `.props`, `.slnx`
 
 MSBuild files, in addition to the `#if`, `#else`, `#elseif`, `#endif` inside an xml type comment, a **Condition** expression could be added to an element.  
   
diff --git a/src/Microsoft.TemplateEngine.Orchestrator.RunnableProjects/OperationConfig/OperationConfigDefault.cs b/src/Microsoft.TemplateEngine.Orchestrator.RunnableProjects/OperationConfig/OperationConfigDefault.cs
index 1f76c689113..bd3853aa221 100644
--- a/src/Microsoft.TemplateEngine.Orchestrator.RunnableProjects/OperationConfig/OperationConfigDefault.cs
+++ b/src/Microsoft.TemplateEngine.Orchestrator.RunnableProjects/OperationConfig/OperationConfigDefault.cs
@@ -110,7 +110,7 @@ internal OperationConfigDefault(string glob, string flagPrefix, EvaluatorType ev
                         new OperationConfigDefault("**/*.xaml", "<!--", EvaluatorType.CPP, ConditionalType.Xml),
                         new OperationConfigDefault("**/*.axaml", "<!--", EvaluatorType.CPP, ConditionalType.Xml),
                         new OperationConfigDefault("**/*.sln", "#-", EvaluatorType.CPP, ConditionalType.HashSignLineComment),
-                        new OperationConfigDefault("**/*.slnx", "#-", EvaluatorType.CPP, ConditionalType.Xml),
+                        new OperationConfigDefault("**/*.slnx", "<!--/", EvaluatorType.MSBuild, ConditionalType.MSBuild),
                         new OperationConfigDefault("**/*.yaml", "#-", EvaluatorType.CPP, ConditionalType.HashSignLineComment),
                         new OperationConfigDefault("**/*.yml", "#-", EvaluatorType.CPP, ConditionalType.HashSignLineComment),
                         new OperationConfigDefault("**/Dockerfile", "#-", EvaluatorType.CPP, ConditionalType.HashSignLineComment),