diff --git a/accessible/src/html/nsHyperTextAccessible.cpp b/accessible/src/html/nsHyperTextAccessible.cpp
index d564a882a7f..b5a51733c77 100644
--- a/accessible/src/html/nsHyperTextAccessible.cpp
+++ b/accessible/src/html/nsHyperTextAccessible.cpp
@@ -423,11 +423,14 @@ nsHyperTextAccessible::GetText(PRInt32 aStartOffset, PRInt32 aEndOffset,
     return NS_ERROR_FAILURE;
 
   PRInt32 startOffset = ConvertMagicOffset(aStartOffset);
-  PRInt32 startChildIdx = GetChildIndexAtOffset(startOffset);
-  if (startChildIdx == -1)
-    return NS_ERROR_INVALID_ARG;
-
   PRInt32 endOffset = ConvertMagicOffset(aEndOffset);
+
+  PRInt32 startChildIdx = GetChildIndexAtOffset(startOffset);
+  if (startChildIdx == -1) {
+    // 0 offsets are considered valid for empty text.
+    return (startOffset == 0 && endOffset == 0) ? NS_OK : NS_ERROR_INVALID_ARG;
+  }
+
   PRInt32 endChildIdx = GetChildIndexAtOffset(endOffset);
   if (endChildIdx == -1)
     return NS_ERROR_INVALID_ARG;
diff --git a/accessible/tests/mochitest/text/test_hypertext.html b/accessible/tests/mochitest/text/test_hypertext.html
index c2a63f298b4..c965de489ed 100644
--- a/accessible/tests/mochitest/text/test_hypertext.html
+++ b/accessible/tests/mochitest/text/test_hypertext.html
@@ -21,6 +21,14 @@
   <script type="application/javascript">
     function doTest()
     {
+      //////////////////////////////////////////////////////////////////////////
+      // null getText
+      //////////////////////////////////////////////////////////////////////////
+
+      var emptyTextAcc = getAccessible("nulltext", [nsIAccessibleText]);
+      is(emptyTextAcc.getText(0, -1), "", "getText() END_OF_TEXT with null string");
+      is(emptyTextAcc.getText(0, 0), "", "getText() Len==0 with null string");
+
       //////////////////////////////////////////////////////////////////////////
       // hypertext
       //////////////////////////////////////////////////////////////////////////
@@ -85,11 +93,19 @@
      href="https://bugzilla.mozilla.org/show_bug.cgi?id=638326">
     Bug 638326
   </a>
+  <a target="_blank"
+     title="getText(0, -1) fails with empty text"
+     href="https://bugzilla.mozilla.org/show_bug.cgi?id=749810">
+    Bug 749810
+  </a>
+
   <p id="display"></p>
   <div id="content" style="display: none"></div>
   <pre id="test">
   </pre>
 
+  <div id="nulltext"></div>
+
   <div id="hypertext">hello <a>friend</a> see <img></div>
   <div id="hypertext2">hello <a>friend</a> see <input></div>
   <ol id="list"><li id="listitem">foo</li></ol>