diff --git a/unix/gtkwin.c b/unix/gtkwin.c
index c615367a..3743672a 100644
--- a/unix/gtkwin.c
+++ b/unix/gtkwin.c
@@ -2695,15 +2695,12 @@ int uxsel_input_add(int fd, int rwx) {
     if (rwx & 1) flags |= GDK_INPUT_READ;
     if (rwx & 2) flags |= GDK_INPUT_WRITE;
     if (rwx & 4) flags |= GDK_INPUT_EXCEPTION;
-    if (flags)
-	return gdk_input_add(fd, flags, fd_input_func, NULL);
-    else
-	return -1;
+    assert(flags);
+    return gdk_input_add(fd, flags, fd_input_func, NULL);
 }
 
 void uxsel_input_remove(int id) {
-    if (id > 0)
-	gdk_input_remove(id);
+    gdk_input_remove(id);
 }
 
 char *guess_derived_font_name(GdkFont *font, int bold, int wide)
diff --git a/unix/uxsel.c b/unix/uxsel.c
index 0383faa6..e2979c9a 100644
--- a/unix/uxsel.c
+++ b/unix/uxsel.c
@@ -62,22 +62,18 @@ void uxsel_init(void)
 
 void uxsel_set(int fd, int rwx, uxsel_callback_fn callback)
 {
-    struct fd *newfd = snew(struct fd);
-    struct fd *oldfd;
+    struct fd *newfd;
 
-    newfd->fd = fd;
-    newfd->rwx = rwx;
-    newfd->callback = callback;
+    uxsel_del(fd);
 
-    oldfd = find234(fds, newfd, NULL);
-    if (oldfd) {
-	uxsel_input_remove(oldfd->id);
-	del234(fds, oldfd);
-	sfree(oldfd);
+    if (rwx) {
+	newfd = snew(struct fd);
+	newfd->fd = fd;
+	newfd->rwx = rwx;
+	newfd->callback = callback;
+	newfd->id = uxsel_input_add(fd, rwx);
+	add234(fds, newfd);
     }
-
-    add234(fds, newfd);
-    newfd->id = uxsel_input_add(fd, rwx);
 }
 
 void uxsel_del(int fd)