diff --git a/kwin/fire/onSettingsChanged.js b/kwin/fire/onSettingsChanged.js
index 3b20add..d6ef48d 100644
--- a/kwin/fire/onSettingsChanged.js
+++ b/kwin/fire/onSettingsChanged.js
@@ -2,6 +2,7 @@
 // The code below is called whenever the user changes something in the configuration of
 // the effect.
 
+effect.setUniform(this.shader, 'uDuration', this.duration * 0.001);
 effect.setUniform(this.shader, 'u3DNoise',
                   effect.readConfig('3DNoise', true) ? 1.0 : 0.0);
 effect.setUniform(this.shader, 'uScale', effect.readConfig('Scale', 1.0));
diff --git a/kwin/wisps/onSettingsChanged.js b/kwin/wisps/onSettingsChanged.js
index 6a8173e..6928ce8 100644
--- a/kwin/wisps/onSettingsChanged.js
+++ b/kwin/wisps/onSettingsChanged.js
@@ -2,5 +2,6 @@
 // The code below is called whenever the user changes something in the configuration of
 // the effect.
 
+effect.setUniform(this.shader, 'uDuration', this.duration * 0.001);
 effect.setUniform(this.shader, 'uScale', effect.readConfig('Scale', 1.0));
 effect.setUniform(this.shader, 'uColor', effect.readConfig('Color', 'white'));