diff --git a/dom/media/webaudio/AnalyserNode.cpp b/dom/media/webaudio/AnalyserNode.cpp
index dcbc1a645b7d..9cd1808d3df4 100644
--- a/dom/media/webaudio/AnalyserNode.cpp
+++ b/dom/media/webaudio/AnalyserNode.cpp
@@ -245,7 +245,9 @@ AnalyserNode::GetFloatFrequencyData(const Float32Array& aArray)
   size_t length = std::min(size_t(aArray.Length()), mOutputBuffer.Length());
 
   for (size_t i = 0; i < length; ++i) {
-    buffer[i] = WebAudioUtils::ConvertLinearToDecibels(mOutputBuffer[i], mMinDecibels);
+    buffer[i] =
+      WebAudioUtils::ConvertLinearToDecibels(mOutputBuffer[i],
+                                             -std::numeric_limits<float>::infinity());
   }
 }
 
diff --git a/dom/media/webaudio/test/mochitest.ini b/dom/media/webaudio/test/mochitest.ini
index 8247dddcbb55..12fe71b07b7e 100644
--- a/dom/media/webaudio/test/mochitest.ini
+++ b/dom/media/webaudio/test/mochitest.ini
@@ -33,6 +33,7 @@ support-files =
 [test_analyserNodeOutput.html]
 [test_analyserNodePassThrough.html]
 [test_analyserNodeWithGain.html]
+[test_analyserNodeMinimum.html]
 [test_AudioBuffer.html]
 [test_audioBufferSourceNode.html]
 [test_audioBufferSourceNodeEnded.html]
diff --git a/dom/media/webaudio/test/test_analyserNodeMinimum.html b/dom/media/webaudio/test/test_analyserNodeMinimum.html
new file mode 100644
index 000000000000..e8a2f64ecb5a
--- /dev/null
+++ b/dom/media/webaudio/test/test_analyserNodeMinimum.html
@@ -0,0 +1,51 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>Test AnalyserNode when the input is silent</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="webaudio.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
+</head>
+<body>
+<pre id="test">
+<script class="testbody" type="text/javascript">
+
+SimpleTest.waitForExplicitFinish();
+addLoadEvent(function() {
+
+  var ac = new AudioContext();
+  var analyser = ac.createAnalyser();
+  var constant = ac.createConstantSource();
+  var sp = ac.createScriptProcessor(2048, 1, 0);
+
+  constant.offset.value = 0.0;
+
+  constant.connect(analyser)
+          .connect(ac.destination);
+
+  constant.connect(sp);
+
+  var buf = new Float32Array(analyser.frequencyBinCount);
+  var iteration_count = 10;
+  sp.onaudioprocess = function() {
+    analyser.getFloatFrequencyData(buf);
+    var correct = true;
+    for (var i = 0; i < buf.length; i++) {
+     correct &= buf[i] == -Infinity;
+    }
+    ok(correct, "silent input process -Infinity in decibel bins");
+    if(!(iteration_count--)) {
+      sp.onaudioprocess = null;
+      constant.stop();
+      ac.close();
+      SimpleTest.finish();
+    }
+  }
+
+  constant.start();
+});
+
+</script>
+</pre>
+</body>
+</html>
