diff --git a/include/boost/detail/sp_counted_base_cw_ppc.hpp b/include/boost/detail/sp_counted_base_cw_ppc.hpp
index f937d2a..b44178f 100644
--- a/include/boost/detail/sp_counted_base_cw_ppc.hpp
+++ b/include/boost/detail/sp_counted_base_cw_ppc.hpp
@@ -121,7 +121,7 @@ public:
 
     void release() // nothrow
     {
-        if( atomic_decrement( &use_count_, -1 ) == 0 )
+        if( atomic_decrement( &use_count_ ) == 0 )
         {
             dispose();
             weak_release();
@@ -135,7 +135,7 @@ public:
 
     void weak_release() // nothrow
     {
-        if( atomic_decrement( &weak_count_, -1 ) == 0 )
+        if( atomic_decrement( &weak_count_ ) == 0 )
         {
             destroy();
         }
diff --git a/include/boost/detail/sp_counted_base_gcc_ppc.hpp b/include/boost/detail/sp_counted_base_gcc_ppc.hpp
index 9a6b609..80ef987 100644
--- a/include/boost/detail/sp_counted_base_gcc_ppc.hpp
+++ b/include/boost/detail/sp_counted_base_gcc_ppc.hpp
@@ -148,7 +148,7 @@ public:
 
     void release() // nothrow
     {
-        if( atomic_decrement( &use_count_, -1 ) == 0 )
+        if( atomic_decrement( &use_count_ ) == 0 )
         {
             dispose();
             weak_release();
@@ -162,7 +162,7 @@ public:
 
     void weak_release() // nothrow
     {
-        if( atomic_decrement( &weak_count_, -1 ) == 0 )
+        if( atomic_decrement( &weak_count_ ) == 0 )
         {
             destroy();
         }