diff --git a/xpra/gtk/configure/gstreamer.py b/xpra/gtk/configure/gstreamer.py
index efaf8bfc18..95392b7e37 100644
--- a/xpra/gtk/configure/gstreamer.py
+++ b/xpra/gtk/configure/gstreamer.py
@@ -5,10 +5,10 @@
 
 import shlex
 from textwrap import wrap
-from subprocess import Popen, PIPE
+from subprocess import Popen, PIPE, check_call
 
 from xpra.util.types import AtomicInteger
-from xpra.os_util import is_X11, is_gnome, OSX, WIN32
+from xpra.os_util import is_X11, is_gnome, OSX, WIN32, POSIX
 from xpra.gtk.dialogs.base_gui_window import BaseGUIWindow
 from xpra.gtk.widget import label, slabel, title_box
 from xpra.platform.paths import get_image
@@ -30,6 +30,10 @@
 EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 """.replace("\n", "")
 
+def sync() -> None:
+    if POSIX:
+        check_call("sync")
+
 
 class ConfigureGUI(BaseGUIWindow):
 
@@ -139,7 +143,7 @@ def run_test_cmd(cmd):
                 log.error(f"Error running {cmd!r}: {e}")
                 set_label(f"Error: {e}")
             return False
-
+        sync()
         #first make sure that the element exists:
         if not run_test_cmd(["gst-inspect-1.0", element]):
             return
@@ -148,7 +152,6 @@ def run_test_cmd(cmd):
             return
         set_label("Test pipeline worked")
 
-
     def populate_with_warning(self):
         layout = Gtk.Layout()
         layout.set_margin_top(0)
@@ -186,6 +189,7 @@ def main(_args) -> int:
     from xpra.gtk.configure.main import run_gui
     return run_gui(ConfigureGUI)
 
+
 if __name__ == "__main__":
     import sys
     sys.exit(main(sys.argv[1:]))