diff --git a/psychopy/visual/movie3.py b/psychopy/visual/movie3.py
index e13fc22751..dfc94da3d3 100644
--- a/psychopy/visual/movie3.py
+++ b/psychopy/visual/movie3.py
@@ -119,7 +119,7 @@ def __init__(self, win,
         self.flipHoriz = flipHoriz
         self.pos = numpy.asarray(pos, float)
         self.depth = depth
-        self.opacity = float(opacity)
+        self.opacity = opacity
         self.interpolate = interpolate
         self.noAudio = noAudio
         self._audioStream = None