diff --git a/embedding/components/find/nsFind.cpp b/embedding/components/find/nsFind.cpp
index 6987c11d3..63304dafb 100644
--- a/embedding/components/find/nsFind.cpp
+++ b/embedding/components/find/nsFind.cpp
@@ -932,7 +932,7 @@ nsFind::ResetAll()
 // Take nodes out of the tree with NextNode, until null (NextNode will return 0
 // at the end of our range).
 NS_IMETHODIMP
-nsFind::Find(const char16_t* aPatText, nsIDOMRange* aSearchRange,
+nsFind::Find(const nsAString& aPatText, nsIDOMRange* aSearchRange,
              nsIDOMRange* aStartPoint, nsIDOMRange* aEndPoint,
              nsIDOMRange** aRangeRet)
 {
@@ -949,10 +949,6 @@ nsFind::Find(const char16_t* aPatText, nsIDOMRange* aSearchRange,
   NS_ENSURE_ARG_POINTER(aRangeRet);
   *aRangeRet = 0;
 
-  if (!aPatText) {
-    return NS_ERROR_NULL_POINTER;
-  }
-
   ResetAll();
 
   nsAutoString patAutoStr(aPatText);
diff --git a/embedding/components/find/nsIFind.idl b/embedding/components/find/nsIFind.idl
index 2c9b17703..ce02c9b7d 100644
--- a/embedding/components/find/nsIFind.idl
+++ b/embedding/components/find/nsIFind.idl
@@ -29,6 +29,6 @@ interface nsIFind : nsISupports
    *                     end (forward) or start (backward).
    * @retval             A range spanning the match that was found (or null).
    */
-  nsIDOMRange Find(in wstring aPatText, in nsIDOMRange aSearchRange,
+  nsIDOMRange Find(in AString aPatText, in nsIDOMRange aSearchRange,
                    in nsIDOMRange aStartPoint, in nsIDOMRange aEndPoint);
 };
diff --git a/embedding/components/find/nsWebBrowserFind.cpp b/embedding/components/find/nsWebBrowserFind.cpp
index af44ce59b..aadc66f8e 100644
--- a/embedding/components/find/nsWebBrowserFind.cpp
+++ b/embedding/components/find/nsWebBrowserFind.cpp
@@ -751,7 +751,7 @@ nsWebBrowserFind::SearchInFrame(nsPIDOMWindowOuter* aWindow, bool aWrapping,
 
   NS_ENSURE_SUCCESS(rv, rv);
 
-  rv = find->Find(mSearchString.get(), searchRange, startPt, endPt,
+  rv = find->Find(mSearchString, searchRange, startPt, endPt,
                   getter_AddRefs(foundRange));
 
   if (NS_SUCCEEDED(rv) && foundRange) {
diff --git a/embedding/test/test_nsFind.html b/embedding/test/test_nsFind.html
index 5f5a4687a..f180cda20 100644
--- a/embedding/test/test_nsFind.html
+++ b/embedding/test/test_nsFind.html
@@ -33,20 +33,6 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=450048
   var startPt = searchRange;
   var endPt = searchRange;
 
-  // Check |null| detection on |aPatText| parameter.
-  try {
-    rf.Find(null, searchRange, startPt, endPt);
-
-    ok(false, "Missing NS_ERROR_NULL_POINTER exception");
-  } catch (e) {
-    e = SpecialPowers.wrap(e);
-    if (e.result == SpecialPowers.Cr.NS_ERROR_NULL_POINTER) {
-      ok(true, null);
-    } else {
-      throw e;
-    }
-  }
-
   // Check |null| detection on |aSearchRange| parameter.
   try {
     rf.Find("", null, startPt, endPt);
diff --git a/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp b/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp
index 674681581..53b1ef66d 100644
--- a/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp
+++ b/toolkit/components/typeaheadfind/nsTypeAheadFind.cpp
@@ -420,7 +420,7 @@ nsTypeAheadFind::FindItNow(nsIPresShell *aPresShell, bool aIsLinksOnly,
 
   while (true) {    // ----- Outer while loop: go through all docs -----
     while (true) {  // === Inner while loop: go through a single doc ===
-      mFind->Find(mTypeAheadBuffer.get(), mSearchRange, mStartPointRange,
+      mFind->Find(mTypeAheadBuffer, mSearchRange, mStartPointRange,
                   mEndPointRange, getter_AddRefs(returnRange));
       
       if (!returnRange)