diff --git a/src/libstd/sys/unix/thread.rs b/src/libstd/sys/unix/thread.rs
index a5b34eeec289e..75d0d13a4b517 100644
--- a/src/libstd/sys/unix/thread.rs
+++ b/src/libstd/sys/unix/thread.rs
@@ -183,7 +183,7 @@ impl Thread {
         unsafe {
             let ret = libc::pthread_join(self.id, ptr::null_mut());
             mem::forget(self);
-            assert!(ret == 0, "failed to join thread: {}", io::Error::from_raw_os_error(ret));
+            debug_assert_eq!(ret, 0);
         }
     }
 
diff --git a/src/libstd/sys/windows/c.rs b/src/libstd/sys/windows/c.rs
index b1f9d9766f705..c07af0fc8390d 100644
--- a/src/libstd/sys/windows/c.rs
+++ b/src/libstd/sys/windows/c.rs
@@ -254,7 +254,6 @@ pub const FILE_END: DWORD = 2;
 
 pub const WAIT_OBJECT_0: DWORD = 0x00000000;
 pub const WAIT_TIMEOUT: DWORD = 258;
-pub const WAIT_FAILED: DWORD = 0xFFFFFFFF;
 
 pub const PIPE_ACCESS_INBOUND: DWORD = 0x00000001;
 pub const PIPE_ACCESS_OUTBOUND: DWORD = 0x00000002;
diff --git a/src/libstd/sys/windows/thread.rs b/src/libstd/sys/windows/thread.rs
index c828243a59b11..891cd4c6e39b0 100644
--- a/src/libstd/sys/windows/thread.rs
+++ b/src/libstd/sys/windows/thread.rs
@@ -65,10 +65,7 @@ impl Thread {
     }
 
     pub fn join(self) {
-        let rc = unsafe { c::WaitForSingleObject(self.handle.raw(), c::INFINITE) };
-        if rc == c::WAIT_FAILED {
-            panic!("failed to join on thread: {}", io::Error::last_os_error());
-        }
+        unsafe { c::WaitForSingleObject(self.handle.raw(), c::INFINITE); }
     }
 
     pub fn yield_now() {
diff --git a/src/libstd/thread/mod.rs b/src/libstd/thread/mod.rs
index 0c632d2afbdd4..025891db4be08 100644
--- a/src/libstd/thread/mod.rs
+++ b/src/libstd/thread/mod.rs
@@ -1447,11 +1447,6 @@ impl<T> JoinHandle<T> {
     /// [`panic`]: ../../std/macro.panic.html
     /// [atomic memory orderings]: ../../std/sync/atomic/index.html
     ///
-    /// # Panics
-    ///
-    /// This function may panic on some platforms if a thread attempts to join
-    /// itself or otherwise may create a deadlock with joining threads.
-    ///
     /// # Examples
     ///
     /// ```