diff --git a/src/nmap.rs b/src/nmap.rs
index b54d022..f2358a0 100644
--- a/src/nmap.rs
+++ b/src/nmap.rs
@@ -8,7 +8,7 @@ lazy_static! {
     static ref NMAP_DNS_RESOLVERS: String = resolver_engine::RESOLVERS
         .clone()
         .iter()
-        .map(|f| f.to_string())
+        .map(ToString::to_string)
         .collect::<Vec<String>>()
         .join(",");
 }