diff --git a/src/platform/redox/ptrace.rs b/src/platform/redox/ptrace.rs
index b2933a9520..9022675144 100644
--- a/src/platform/redox/ptrace.rs
+++ b/src/platform/redox/ptrace.rs
@@ -52,6 +52,8 @@ pub fn init_state() -> &'static State {
     }
 }
 pub fn is_traceme(pid: pid_t) -> bool {
+    // Skip special PIDs (<=0)
+    if pid <= 0 { return false; }
     File::open(
         &CString::new(format!("chan:ptrace-relibc/{}/traceme", pid)).unwrap(),
         fcntl::O_PATH,