1 files changed, 3 insertions, 1 deletions
diff --git a/io.c b/io.c
index d53f9c0df2..eb12d95fe4 100644
--- a/io.c
+++ b/io.c
@@ -6201,12 +6201,14 @@ fptr_copy_finalizer(rb_io_t *fptr, const rb_io_t *orig)
 {
 #if defined(__CYGWIN__) || !defined(HAVE_WORKING_FORK)
     void (*const old_finalize)(struct rb_io_t*,int) = fptr->finalize;
+
+    if (old_finalize == fptr->finalize) return;
 #endif
 
     fptr->finalize = orig->finalize;
 
 #if defined(__CYGWIN__) || !defined(HAVE_WORKING_FORK)
-    if (old_finalize == pipe_finalize) {
+    if (old_finalize != pipe_finalize) {
 	struct pipe_list *list;
 	for (list = pipe_list; list; list = list->next) {
 	    if (list->fptr == fptr) break;