diff --git a/editor/base/nsHTMLEditRules.cpp b/editor/base/nsHTMLEditRules.cpp
index 79f45d7c3ff2..1c5e01c11778 100644
--- a/editor/base/nsHTMLEditRules.cpp
+++ b/editor/base/nsHTMLEditRules.cpp
@@ -4210,7 +4210,7 @@ nsHTMLEditRules::DoTextNodeWhitespace(nsIDOMCharacterData *aTextNode, PRInt32 aS
 
 
 nsresult 
-nsHTMLEditRules::ConvertWhitespace(const nsString & inString, const nsString & outString)
+nsHTMLEditRules::ConvertWhitespace(const nsString & inString, nsString & outString)
 {
   PRUint32 j,len = inString.Length();
   switch (len)
diff --git a/editor/base/nsHTMLEditRules.h b/editor/base/nsHTMLEditRules.h
index 2345f61ba312..ddb37efc4a6a 100644
--- a/editor/base/nsHTMLEditRules.h
+++ b/editor/base/nsHTMLEditRules.h
@@ -168,7 +168,7 @@ protected:
   nsresult DoTextNodeWhitespace(nsIDOMCharacterData *aTextNode, PRInt32 aStart, PRInt32 aEnd);
   nsresult UpdateDocChangeRange(nsIDOMRange *aRange);
 
-  nsresult ConvertWhitespace(const nsString & inString, const nsString & outString);
+  nsresult ConvertWhitespace(const nsString & inString, nsString & outString);
 
 // removed from use:
 #if 0
diff --git a/editor/libeditor/html/nsHTMLEditRules.cpp b/editor/libeditor/html/nsHTMLEditRules.cpp
index 79f45d7c3ff2..1c5e01c11778 100644
--- a/editor/libeditor/html/nsHTMLEditRules.cpp
+++ b/editor/libeditor/html/nsHTMLEditRules.cpp
@@ -4210,7 +4210,7 @@ nsHTMLEditRules::DoTextNodeWhitespace(nsIDOMCharacterData *aTextNode, PRInt32 aS
 
 
 nsresult 
-nsHTMLEditRules::ConvertWhitespace(const nsString & inString, const nsString & outString)
+nsHTMLEditRules::ConvertWhitespace(const nsString & inString, nsString & outString)
 {
   PRUint32 j,len = inString.Length();
   switch (len)
diff --git a/editor/libeditor/html/nsHTMLEditRules.h b/editor/libeditor/html/nsHTMLEditRules.h
index 2345f61ba312..ddb37efc4a6a 100644
--- a/editor/libeditor/html/nsHTMLEditRules.h
+++ b/editor/libeditor/html/nsHTMLEditRules.h
@@ -168,7 +168,7 @@ protected:
   nsresult DoTextNodeWhitespace(nsIDOMCharacterData *aTextNode, PRInt32 aStart, PRInt32 aEnd);
   nsresult UpdateDocChangeRange(nsIDOMRange *aRange);
 
-  nsresult ConvertWhitespace(const nsString & inString, const nsString & outString);
+  nsresult ConvertWhitespace(const nsString & inString, nsString & outString);
 
 // removed from use:
 #if 0