diff --git a/mozilla/string/obsolete/nsString.cpp b/mozilla/string/obsolete/nsString.cpp
index abc2cf62e98..ba1a7612f6f 100644
--- a/mozilla/string/obsolete/nsString.cpp
+++ b/mozilla/string/obsolete/nsString.cpp
@@ -1704,7 +1704,7 @@ nsCAutoString::nsCAutoString(const char* aCString,PRInt32 aLength) : nsCString()
  * Copy construct from ascii c-string
  * @param   aCString is a ptr to a 1-byte cstr
  */
-nsCAutoString::nsCAutoString(CBufDescriptor& aBuffer) : nsCString() {
+nsCAutoString::nsCAutoString(const CBufDescriptor& aBuffer) : nsCString() {
   mAgent=0;
   if(!aBuffer.mBuffer) {
     nsStr::Initialize(*this,mBuffer,sizeof(mBuffer)-1,0,eOneByte,PR_FALSE);
diff --git a/mozilla/string/obsolete/nsString.h b/mozilla/string/obsolete/nsString.h
index 3d1bedb67ca..9708bb6ecf1 100644
--- a/mozilla/string/obsolete/nsString.h
+++ b/mozilla/string/obsolete/nsString.h
@@ -706,7 +706,7 @@ public:
 
     nsCAutoString();
     nsCAutoString(const char* aString,PRInt32 aLength=-1);
-    nsCAutoString(CBufDescriptor& aBuffer);
+    nsCAutoString(const CBufDescriptor& aBuffer);
     nsCAutoString(const PRUnichar* aString,PRInt32 aLength=-1);
     nsCAutoString(const nsStr& aString);
     nsCAutoString(const nsCAutoString& aString);
diff --git a/mozilla/xpcom/ds/nsString.cpp b/mozilla/xpcom/ds/nsString.cpp
index abc2cf62e98..ba1a7612f6f 100644
--- a/mozilla/xpcom/ds/nsString.cpp
+++ b/mozilla/xpcom/ds/nsString.cpp
@@ -1704,7 +1704,7 @@ nsCAutoString::nsCAutoString(const char* aCString,PRInt32 aLength) : nsCString()
  * Copy construct from ascii c-string
  * @param   aCString is a ptr to a 1-byte cstr
  */
-nsCAutoString::nsCAutoString(CBufDescriptor& aBuffer) : nsCString() {
+nsCAutoString::nsCAutoString(const CBufDescriptor& aBuffer) : nsCString() {
   mAgent=0;
   if(!aBuffer.mBuffer) {
     nsStr::Initialize(*this,mBuffer,sizeof(mBuffer)-1,0,eOneByte,PR_FALSE);
diff --git a/mozilla/xpcom/ds/nsString.h b/mozilla/xpcom/ds/nsString.h
index 3d1bedb67ca..9708bb6ecf1 100644
--- a/mozilla/xpcom/ds/nsString.h
+++ b/mozilla/xpcom/ds/nsString.h
@@ -706,7 +706,7 @@ public:
 
     nsCAutoString();
     nsCAutoString(const char* aString,PRInt32 aLength=-1);
-    nsCAutoString(CBufDescriptor& aBuffer);
+    nsCAutoString(const CBufDescriptor& aBuffer);
     nsCAutoString(const PRUnichar* aString,PRInt32 aLength=-1);
     nsCAutoString(const nsStr& aString);
     nsCAutoString(const nsCAutoString& aString);
diff --git a/mozilla/xpcom/string/obsolete/nsString.cpp b/mozilla/xpcom/string/obsolete/nsString.cpp
index abc2cf62e98..ba1a7612f6f 100644
--- a/mozilla/xpcom/string/obsolete/nsString.cpp
+++ b/mozilla/xpcom/string/obsolete/nsString.cpp
@@ -1704,7 +1704,7 @@ nsCAutoString::nsCAutoString(const char* aCString,PRInt32 aLength) : nsCString()
  * Copy construct from ascii c-string
  * @param   aCString is a ptr to a 1-byte cstr
  */
-nsCAutoString::nsCAutoString(CBufDescriptor& aBuffer) : nsCString() {
+nsCAutoString::nsCAutoString(const CBufDescriptor& aBuffer) : nsCString() {
   mAgent=0;
   if(!aBuffer.mBuffer) {
     nsStr::Initialize(*this,mBuffer,sizeof(mBuffer)-1,0,eOneByte,PR_FALSE);
diff --git a/mozilla/xpcom/string/obsolete/nsString.h b/mozilla/xpcom/string/obsolete/nsString.h
index 3d1bedb67ca..9708bb6ecf1 100644
--- a/mozilla/xpcom/string/obsolete/nsString.h
+++ b/mozilla/xpcom/string/obsolete/nsString.h
@@ -706,7 +706,7 @@ public:
 
     nsCAutoString();
     nsCAutoString(const char* aString,PRInt32 aLength=-1);
-    nsCAutoString(CBufDescriptor& aBuffer);
+    nsCAutoString(const CBufDescriptor& aBuffer);
     nsCAutoString(const PRUnichar* aString,PRInt32 aLength=-1);
     nsCAutoString(const nsStr& aString);
     nsCAutoString(const nsCAutoString& aString);