diff --git a/include/boost/checked_delete.hpp b/include/boost/checked_delete.hpp
index 80f936a..9bb84e8 100644
--- a/include/boost/checked_delete.hpp
+++ b/include/boost/checked_delete.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/current_function.hpp b/include/boost/current_function.hpp
index 7b0d918..a135881 100644
--- a/include/boost/current_function.hpp
+++ b/include/boost/current_function.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/ref.hpp b/include/boost/ref.hpp
index eae86f8..e31b167 100644
--- a/include/boost/ref.hpp
+++ b/include/boost/ref.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