diff --git a/content/media/test/manifest.js b/content/media/test/manifest.js
index 2cf93de597a..00a1171be10 100644
--- a/content/media/test/manifest.js
+++ b/content/media/test/manifest.js
@@ -16,7 +16,7 @@ var gSmallTests = [
 // during resource download.
 var gProgressTests = [
   { name:"r11025_u8_c1.wav", type:"audio/x-wav", duration:1.0, size:11069 },
-  { name:"big.wav", type:"audio/x-wav", duration:9.0, size:102444 },
+  { name:"big.wav", type:"audio/x-wav", duration:9.278981, size:102444 },
   { name:"seek.ogv", type:"video/ogg", duration:3.966, size:285310 },
   { name:"320x240.ogv", type:"video/ogg", width:320, height:240, duration:0.233, size:28942 },
   { name:"seek.webm", type:"video/webm", duration:3.966, size:215529 },
@@ -272,7 +272,7 @@ var gDecodeErrorTests = [
 
 // These are files that are used for media fragments tests
 var gFragmentTests = [
-  { name:"big.wav", type:"audio/x-wav", duration:9.28, size:102444 }
+  { name:"big.wav", type:"audio/x-wav", duration:9.278981, size:102444 }
 ];