diff --git a/lib/mpl_toolkits/mplot3d/art3d.py b/lib/mpl_toolkits/mplot3d/art3d.py
index 39727ca60614..adf444b6c883 100644
--- a/lib/mpl_toolkits/mplot3d/art3d.py
+++ b/lib/mpl_toolkits/mplot3d/art3d.py
@@ -686,6 +686,7 @@ def set_alpha(self, alpha):
         try:
             self._facecolors = mcolors.to_rgba_array(
                 self._facecolors3d, self._alpha)
+            self._facecolors3d = self._facecolors
         except (AttributeError, TypeError, IndexError):
             pass
         try: