diff --git a/lib/matplotlib/backends/backend_gtk3.py b/lib/matplotlib/backends/backend_gtk3.py
index 888f5a770f5d..4e05119aa0f6 100644
--- a/lib/matplotlib/backends/backend_gtk3.py
+++ b/lib/matplotlib/backends/backend_gtk3.py
@@ -18,6 +18,13 @@
     # :raises ValueError: If module/version is already loaded, already
     # required, or unavailable.
     gi.require_version("Gtk", "3.0")
+    # Also require GioUnix to avoid PyGIWarning when Gio is imported
+    # GioUnix is platform-specific and may not be available on all systems
+    try:
+        gi.require_version("GioUnix", "2.0")
+    except ValueError:
+        # GioUnix is not available on this platform, which is fine
+        pass
 except ValueError as e:
     # in this case we want to re-raise as ImportError so the
     # auto-backend selection logic correctly skips.
diff --git a/lib/matplotlib/backends/backend_gtk4.py b/lib/matplotlib/backends/backend_gtk4.py
index cd38968779ed..a45fa0bc490f 100644
--- a/lib/matplotlib/backends/backend_gtk4.py
+++ b/lib/matplotlib/backends/backend_gtk4.py
@@ -17,6 +17,13 @@
     # :raises ValueError: If module/version is already loaded, already
     # required, or unavailable.
     gi.require_version("Gtk", "4.0")
+    # Also require GioUnix to avoid PyGIWarning when Gio is imported
+    # GioUnix is platform-specific and may not be available on all systems
+    try:
+        gi.require_version("GioUnix", "2.0")
+    except ValueError:
+        # GioUnix is not available on this platform, which is fine
+        pass
 except ValueError as e:
     # in this case we want to re-raise as ImportError so the
     # auto-backend selection logic correctly skips.