diff --git a/docs/examples/tooltip-viewport/index.html b/docs/examples/tooltip-viewport/index.html
index 4a0c5e1daf..d25a6af4c0 100644
--- a/docs/examples/tooltip-viewport/index.html
+++ b/docs/examples/tooltip-viewport/index.html
@@ -29,19 +29,19 @@
 
   <body>
 
-    <button class="btn btn-default pull-right tooltip-bottom" title="This should be shifted to the left">Shift Left</button>
-    <button class="btn btn-default tooltip-bottom" title="This should be shifted to the right">Shift Right</button>
-    <button class="btn btn-default tooltip-right" title="This should be shifted down">Shift Down</button>
+    <button type="button" class="btn btn-default pull-right tooltip-bottom" title="This should be shifted to the left">Shift Left</button>
+    <button type="button" class="btn btn-default tooltip-bottom" title="This should be shifted to the right">Shift Right</button>
+    <button type="button" class="btn btn-default tooltip-right" title="This should be shifted down">Shift Down</button>
 
-    <button class="btn btn-default tooltip-right btn-bottom" title="This should be shifted up">Shift Up</button>
+    <button type="button" class="btn btn-default tooltip-right btn-bottom" title="This should be shifted up">Shift Up</button>
 
     <div class="container-viewport">
-      <button class="btn btn-default tooltip-viewport-bottom" title="This should be shifted to the left">Shift Left</button>
-      <button class="btn btn-default tooltip-viewport-right" title="This should be shifted down">Shift Down</button>
+      <button type="button" class="btn btn-default tooltip-viewport-bottom" title="This should be shifted to the left">Shift Left</button>
+      <button type="button" class="btn btn-default tooltip-viewport-right" title="This should be shifted down">Shift Down</button>
 
-      <button class="btn btn-default pull-right tooltip-viewport-bottom" title="This should be shifted to the right">Shift Right</button>
+      <button type="button" class="btn btn-default pull-right tooltip-viewport-bottom" title="This should be shifted to the right">Shift Right</button>
 
-      <button class="btn btn-default tooltip-viewport-right btn-bottom" title="This should be shifted up">Shift Up</button>
+      <button type="button" class="btn btn-default tooltip-viewport-right btn-bottom" title="This should be shifted up">Shift Up</button>
     </div>
 
 
