2 files changed, 4 insertions, 4 deletions
diff --git a/io.c b/io.c
index 0db981e39c..5e04da806b 100644
--- a/io.c
+++ b/io.c
@@ -8037,7 +8037,7 @@ FILE *
 rb_io_stdio_file(rb_io_t *fptr)
 {
     if (!fptr->stdio_file) {
-        int oflags = rb_io_fmode_oflags(fptr->mode);
+        int oflags = rb_io_fmode_oflags(fptr->mode) & ~O_EXCL;
         fptr->stdio_file = rb_fdopen(fptr->fd, rb_io_oflags_modestr(oflags));
     }
     return fptr->stdio_file;
diff --git a/test/objspace/test_objspace.rb b/test/objspace/test_objspace.rb
index 983bd59e9a..602773b6cc 100644
--- a/test/objspace/test_objspace.rb
+++ b/test/objspace/test_objspace.rb
@@ -406,10 +406,10 @@ class TestObjSpace < Test::Unit::TestCase
 
         puts dump_my_heap_please
       end;
-      skip if /is not supported/ =~ error
-      skip error unless output
-      assert_match(entry, File.readlines(output).grep(/TEST STRING/).join("\n"))
+      assert_nil(error)
+      dump = File.readlines(output)
       File.unlink(output)
+      assert_match(entry, dump.grep(/TEST STRING/).join("\n"))
     end
 
     if defined?(JSON)