diff --git a/editor/libeditor/nsEditor.cpp b/editor/libeditor/nsEditor.cpp
index bc604c141df5..ba0c1fa99132 100644
--- a/editor/libeditor/nsEditor.cpp
+++ b/editor/libeditor/nsEditor.cpp
@@ -1480,7 +1480,7 @@ nsEditor::JoinNodes(nsINode& aLeftNode, nsINode& aRightNode)
                             parent->AsDOMNode());
   }
 
-  nsresult result;
+  nsresult result = NS_OK;
   RefPtr<JoinNodeTxn> txn = CreateTxnForJoinNode(aLeftNode, aRightNode);
   if (txn)  {
     result = DoTransaction(txn);
diff --git a/editor/libeditor/nsHTMLEditor.cpp b/editor/libeditor/nsHTMLEditor.cpp
index f635c16d8b29..ca5684a5aada 100644
--- a/editor/libeditor/nsHTMLEditor.cpp
+++ b/editor/libeditor/nsHTMLEditor.cpp
@@ -547,7 +547,7 @@ nsHTMLEditor::BeginningOfDocument()
   // Find first editable thingy
   bool done = false;
   nsCOMPtr<nsINode> curNode = rootElement.get(), selNode;
-  int32_t curOffset = 0, selOffset;
+  int32_t curOffset = 0, selOffset = 0;
   while (!done) {
     nsWSRunObject wsObj(this, curNode, curOffset);
     int32_t visOffset = 0;
diff --git a/editor/txtsvc/nsTextServicesDocument.cpp b/editor/txtsvc/nsTextServicesDocument.cpp
index 587b4ad9f9ee..46a6eedf0ec1 100644
--- a/editor/txtsvc/nsTextServicesDocument.cpp
+++ b/editor/txtsvc/nsTextServicesDocument.cpp
@@ -2754,7 +2754,7 @@ nsTextServicesDocument::GetUncollapsedSelection(nsITextServicesDocument::TSDBloc
   nsCOMPtr<nsIDOMNode> startParent, endParent;
   int32_t startOffset, endOffset;
   int32_t rangeCount, tableCount, i;
-  int32_t e1s1, e1s2, e2s1, e2s2;
+  int32_t e1s1 = 0, e1s2 = 0, e2s1 = 0, e2s2 = 0;
 
   OffsetEntry *eStart, *eEnd;
   int32_t eStartOffset, eEndOffset;