diff --git a/include/boost/detail/lightweight_thread.hpp b/include/boost/detail/lightweight_thread.hpp
index 8eba1f8..6fe70a6 100644
--- a/include/boost/detail/lightweight_thread.hpp
+++ b/include/boost/detail/lightweight_thread.hpp
@@ -3,7 +3,7 @@
 
 // MS compatible compilers support #pragma once
 
-#if defined(_MSC_VER)
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
 # pragma once
 #endif
 
diff --git a/include/boost/detail/quick_allocator.hpp b/include/boost/detail/quick_allocator.hpp
index ba048e0..d54b3a7 100644
--- a/include/boost/detail/quick_allocator.hpp
+++ b/include/boost/detail/quick_allocator.hpp
@@ -3,7 +3,7 @@
 
 // MS compatible compilers support #pragma once
 
-#if defined(_MSC_VER)
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
 # pragma once
 #endif