diff --git a/src/platform/redox/mod.rs b/src/platform/redox/mod.rs
index a1cc231e3b..a9334730be 100644
--- a/src/platform/redox/mod.rs
+++ b/src/platform/redox/mod.rs
@@ -1232,10 +1232,11 @@ impl Pal for Sys {
         }
 
         let path = format!("/scheme/time/{clock_id}");
-        let timerfd = FdGuard::open(&path, syscall::O_RDWR)?;
+        let timerfd = FdGuard::open(&path, syscall::O_RDWR)?.to_upper()?;
         let eventfd = FdGuard::new(Error::demux(unsafe {
             event::redox_event_queue_create_v1(0)
-        })?);
+        })?)
+        .to_upper()?;
         let caller_thread = Self::current_os_tid();
 
         let timer_buf = unsafe {
diff --git a/tests/signals/ppoll-block.c b/tests/signals/ppoll-block.c
new file mode 100644
index 0000000000..c56cd07638
--- /dev/null
+++ b/tests/signals/ppoll-block.c
@@ -0,0 +1,51 @@
+#include <errno.h>
+#include <err.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "../test_helpers.h"
+#include "signals_list.h"
+static void handler(int signum)
+{
+    (void) signum;
+    int errnum = errno;
+    printf("SIGUSR1\n");
+    fflush(stdout);
+    errno = errnum;
+}
+
+int main(void)
+{
+    signal(SIGUSR1, handler);
+    sigset_t sigusr1;
+    sigemptyset(&sigusr1);
+    sigaddset(&sigusr1, SIGUSR1);
+    sigprocmask(SIG_BLOCK, &sigusr1, NULL);
+    sigset_t empty;
+    sigemptyset(&empty);
+    int fds[2];
+    if ( pipe(fds) )
+        err(1, "pipe");
+    close(fds[0]);
+    alarm(1); 
+    struct pollfd pfd = { .fd = fds[0], .events = POLLIN };
+    // POSIX requires EINTR or returning the pending events.
+    int ret = ppoll(&pfd, 1, NULL, &empty);
+    if ( ret < 0 )
+        ERROR_IF(ppoll, ret, <0);
+    if ( pfd.revents & POLLIN )
+        ERROR_IF(ppoll, pfd.revents, & POLLIN);
+    if ( pfd.revents & POLLOUT )
+        ERROR_IF(ppoll, pfd.revents, & POLLOUT);
+    if ( pfd.revents & POLLERR )
+        ERROR_IF(ppoll, pfd.revents, & POLLERR);
+    if ( pfd.revents & POLLHUP )
+        ERROR_IF(ppoll, pfd.revents, & POLLHUP);
+    if ( pfd.revents & POLLNVAL ){
+        return EXIT_SUCCESS;
+    }
+    return 0;
+}
\ No newline at end of file