diff --git a/xpcom/base/nscore.h b/xpcom/base/nscore.h
index c1f8ab54676..938b2aa5bfe 100644
--- a/xpcom/base/nscore.h
+++ b/xpcom/base/nscore.h
@@ -258,11 +258,11 @@
  * Deprecated declarations.
  */
 #if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))
-# define NS_DEPRECATED __attribute__((deprecated))
+# define MOZ_DEPRECATED __attribute__((deprecated))
 #elif defined(_MSC_VER) && (_MSC_VER >= 1300)
-# define NS_DEPRECATED __declspec(deprecated)
+# define MOZ_DEPRECATED __declspec(deprecated)
 #else
-# define NS_DEPRECATED
+# define MOZ_DEPRECATED
 #endif
 
 /**
diff --git a/xpcom/idl-parser/header.py b/xpcom/idl-parser/header.py
index 26007e607b0..f541dedce26 100644
--- a/xpcom/idl-parser/header.py
+++ b/xpcom/idl-parser/header.py
@@ -345,7 +345,7 @@ def write_interface(iface, fd):
     if iface.attributes.scriptable:
         fd.write("NS_SCRIPTABLE ")
     if iface.attributes.deprecated:
-        fd.write("NS_DEPRECATED ")
+        fd.write("MOZ_DEPRECATED ")
     fd.write(iface.name)
     if iface.base:
         fd.write(" : public %s" % iface.base)
diff --git a/xpcom/typelib/xpidl/xpidl_header.c b/xpcom/typelib/xpidl/xpidl_header.c
index 1e30398fc01..8d1e0cd237f 100644
--- a/xpcom/typelib/xpidl/xpidl_header.c
+++ b/xpcom/typelib/xpidl/xpidl_header.c
@@ -245,7 +245,7 @@ interface(TreeState *state)
             "class %s%s%s%s",
             (keepvtable ? "" : "NS_NO_VTABLE "),
             (scriptable ? "NS_SCRIPTABLE " : ""),
-            (deprecated ? "NS_DEPRECATED " : ""),
+            (deprecated ? "MOZ_DEPRECATED " : ""),
             className);
     
     if ((iter = IDL_INTERFACE(iface).inheritance_spec)) {
@@ -792,7 +792,7 @@ write_attr_accessor(IDL_tree attr_tree, FILE * outfile,
 
     if (mode == AS_DECL) {
         if (IDL_tree_property_get(ident, "deprecated"))
-            fputs("NS_DEPRECATED ", outfile);
+            fputs("MOZ_DEPRECATED ", outfile);
         if (is_method_scriptable(attr_tree, ident))
             fputs("NS_SCRIPTABLE ", outfile);
 
@@ -1046,7 +1046,7 @@ write_method_signature(IDL_tree method_tree, FILE *outfile, int mode,
 
     if (mode == AS_DECL) {
         if (IDL_tree_property_get(op->ident, "deprecated"))
-            fputs("NS_DEPRECATED ", outfile);
+            fputs("MOZ_DEPRECATED ", outfile);
         if (is_method_scriptable(method_tree, op->ident))
             fputs("NS_SCRIPTABLE ", outfile);