diff --git a/src/builtins/fetch.rs b/src/builtins/fetch.rs
index 89c7592..0f00892 100644
--- a/src/builtins/fetch.rs
+++ b/src/builtins/fetch.rs
@@ -56,3 +56,13 @@ fn format_uptime(uptime: u64) -> String {
 fn bytes_to_mega_bytes(bytes: u64) -> u64 {
     bytes / 1024 / 1024
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_format_uptime_seconds() {
+        assert_eq!(format_uptime(35), "0h 0m 35s");
+    }
+}