diff --git a/src/main.rs b/src/main.rs
index 1e6722c..3e83f49 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -94,7 +94,7 @@ fn crawl(argument: &Argument, output: &Output) -> Result<(), Box<dyn Error>> {
 
         File::create(destination.item())?.write_all(data.join("\n\n").as_bytes())?;
 
-        if !argument.index.is_none() {
+        if argument.index.is_some() {
             index.insert(destination.path); // request index file update in this location
         }
     }