diff --git a/include/boost/scoped_array.hpp b/include/boost/scoped_array.hpp
index 08155e9..e5919a4 100644
--- a/include/boost/scoped_array.hpp
+++ b/include/boost/scoped_array.hpp
@@ -93,7 +93,15 @@ public:
         return ptr != 0;
     }
 
-#else
+#elif defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
+    typedef T * (this_type::*unspecified_bool_type)() const;
+    
+    operator unspecified_bool_type() const // never throws
+    {
+        return ptr == 0? 0: &this_type::get;
+    }
+
+#else 
 
     typedef T * this_type::*unspecified_bool_type;
 
diff --git a/include/boost/scoped_ptr.hpp b/include/boost/scoped_ptr.hpp
index da4aeef..c36cace 100644
--- a/include/boost/scoped_ptr.hpp
+++ b/include/boost/scoped_ptr.hpp
@@ -110,8 +110,15 @@ public:
         return ptr != 0;
     }
 
-#else
+#elif defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
+    typedef T * (this_type::*unspecified_bool_type)() const;
+    
+    operator unspecified_bool_type() const // never throws
+    {
+        return ptr == 0? 0: &this_type::get;
+    }
 
+#else 
     typedef T * this_type::*unspecified_bool_type;
 
     operator unspecified_bool_type() const // never throws
diff --git a/include/boost/shared_array.hpp b/include/boost/shared_array.hpp
index b380879..5e943d9 100644
--- a/include/boost/shared_array.hpp
+++ b/include/boost/shared_array.hpp
@@ -102,7 +102,15 @@ public:
         return px != 0;
     }
 
-#else
+#elif defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
+    typedef T * (this_type::*unspecified_bool_type)() const;
+    
+    operator unspecified_bool_type() const // never throws
+    {
+        return px == 0? 0: &this_type::get;
+    }
+
+#else 
 
     typedef T * this_type::*unspecified_bool_type;
 
diff --git a/include/boost/shared_ptr.hpp b/include/boost/shared_ptr.hpp
index f7d80ae..d4b44e6 100644
--- a/include/boost/shared_ptr.hpp
+++ b/include/boost/shared_ptr.hpp
@@ -269,7 +269,15 @@ public:
         return px != 0;
     }
 
-#else
+#elif defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
+    typedef T * (this_type::*unspecified_bool_type)() const;
+    
+    operator unspecified_bool_type() const // never throws
+    {
+        return px == 0? 0: &this_type::get;
+    }
+
+#else 
 
     typedef T * this_type::*unspecified_bool_type;