diff --git a/mozilla/base/src/nsString.cpp b/mozilla/base/src/nsString.cpp
index df1270bc124..ea4cace6e8d 100644
--- a/mozilla/base/src/nsString.cpp
+++ b/mozilla/base/src/nsString.cpp
@@ -350,7 +350,7 @@ const PRUnichar* nsString::GetUnicode(void) const{
   return mStr;
 }
 
-nsString::operator PRUnichar*() const{
+nsString::operator const PRUnichar*() const{
   return mStr;
 }
 
diff --git a/mozilla/base/src/nsString.h b/mozilla/base/src/nsString.h
index a641dbca3b1..4f38a93c2a7 100644
--- a/mozilla/base/src/nsString.h
+++ b/mozilla/base/src/nsString.h
@@ -136,7 +136,7 @@ const PRUnichar* GetUnicode(void) const;
  * @param 
  * @return
  */
-operator PRUnichar*() const;
+operator const PRUnichar*() const;
 
 /**
  * Retrieve unicode char at given index
diff --git a/mozilla/string/obsolete/nsString.cpp b/mozilla/string/obsolete/nsString.cpp
index df1270bc124..ea4cace6e8d 100644
--- a/mozilla/string/obsolete/nsString.cpp
+++ b/mozilla/string/obsolete/nsString.cpp
@@ -350,7 +350,7 @@ const PRUnichar* nsString::GetUnicode(void) const{
   return mStr;
 }
 
-nsString::operator PRUnichar*() const{
+nsString::operator const PRUnichar*() const{
   return mStr;
 }
 
diff --git a/mozilla/string/obsolete/nsString.h b/mozilla/string/obsolete/nsString.h
index a641dbca3b1..4f38a93c2a7 100644
--- a/mozilla/string/obsolete/nsString.h
+++ b/mozilla/string/obsolete/nsString.h
@@ -136,7 +136,7 @@ const PRUnichar* GetUnicode(void) const;
  * @param 
  * @return
  */
-operator PRUnichar*() const;
+operator const PRUnichar*() const;
 
 /**
  * Retrieve unicode char at given index
diff --git a/mozilla/xpcom/ds/nsString.cpp b/mozilla/xpcom/ds/nsString.cpp
index df1270bc124..ea4cace6e8d 100644
--- a/mozilla/xpcom/ds/nsString.cpp
+++ b/mozilla/xpcom/ds/nsString.cpp
@@ -350,7 +350,7 @@ const PRUnichar* nsString::GetUnicode(void) const{
   return mStr;
 }
 
-nsString::operator PRUnichar*() const{
+nsString::operator const PRUnichar*() const{
   return mStr;
 }
 
diff --git a/mozilla/xpcom/ds/nsString.h b/mozilla/xpcom/ds/nsString.h
index a641dbca3b1..4f38a93c2a7 100644
--- a/mozilla/xpcom/ds/nsString.h
+++ b/mozilla/xpcom/ds/nsString.h
@@ -136,7 +136,7 @@ const PRUnichar* GetUnicode(void) const;
  * @param 
  * @return
  */
-operator PRUnichar*() const;
+operator const PRUnichar*() const;
 
 /**
  * Retrieve unicode char at given index
diff --git a/mozilla/xpcom/string/obsolete/nsString.cpp b/mozilla/xpcom/string/obsolete/nsString.cpp
index df1270bc124..ea4cace6e8d 100644
--- a/mozilla/xpcom/string/obsolete/nsString.cpp
+++ b/mozilla/xpcom/string/obsolete/nsString.cpp
@@ -350,7 +350,7 @@ const PRUnichar* nsString::GetUnicode(void) const{
   return mStr;
 }
 
-nsString::operator PRUnichar*() const{
+nsString::operator const PRUnichar*() const{
   return mStr;
 }
 
diff --git a/mozilla/xpcom/string/obsolete/nsString.h b/mozilla/xpcom/string/obsolete/nsString.h
index a641dbca3b1..4f38a93c2a7 100644
--- a/mozilla/xpcom/string/obsolete/nsString.h
+++ b/mozilla/xpcom/string/obsolete/nsString.h
@@ -136,7 +136,7 @@ const PRUnichar* GetUnicode(void) const;
  * @param 
  * @return
  */
-operator PRUnichar*() const;
+operator const PRUnichar*() const;
 
 /**
  * Retrieve unicode char at given index