diff --git a/src/main.rs b/src/main.rs
index a5d2479..6c1f2e3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -145,6 +145,9 @@ fn controllers(config: &Config, filter: bool) -> std::io::Result<Vec<HwMon>> {
 
 fn service(config: Config) -> std::io::Result<()> {
     let mut controllers = controllers(&config, true)?;
+    if controllers.len() < 1 {
+        return Err(not_found());
+    }
     let mut cache = std::collections::HashMap::new();
     loop {
         for hw_mon in controllers.iter_mut() {