diff --git a/include/boost/unordered/detail/allocate.hpp b/include/boost/unordered/detail/allocate.hpp
index 6671607e..34d135f3 100644
--- a/include/boost/unordered/detail/allocate.hpp
+++ b/include/boost/unordered/detail/allocate.hpp
@@ -9,7 +9,7 @@
 #ifndef BOOST_UNORDERED_ALLOCATE_HPP
 #define BOOST_UNORDERED_ALLOCATE_HPP
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif
 
diff --git a/include/boost/unordered/detail/buckets.hpp b/include/boost/unordered/detail/buckets.hpp
index 95d8df18..041f21f9 100644
--- a/include/boost/unordered/detail/buckets.hpp
+++ b/include/boost/unordered/detail/buckets.hpp
@@ -7,7 +7,7 @@
 #ifndef BOOST_UNORDERED_DETAIL_MANAGER_HPP_INCLUDED
 #define BOOST_UNORDERED_DETAIL_MANAGER_HPP_INCLUDED
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif
 
diff --git a/include/boost/unordered/detail/equivalent.hpp b/include/boost/unordered/detail/equivalent.hpp
index d1c688b8..91c4b49d 100644
--- a/include/boost/unordered/detail/equivalent.hpp
+++ b/include/boost/unordered/detail/equivalent.hpp
@@ -7,7 +7,7 @@
 #ifndef BOOST_UNORDERED_DETAIL_EQUIVALENT_HPP_INCLUDED
 #define BOOST_UNORDERED_DETAIL_EQUIVALENT_HPP_INCLUDED
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif
 
diff --git a/include/boost/unordered/detail/fwd.hpp b/include/boost/unordered/detail/fwd.hpp
index ee8966b7..66fa3320 100644
--- a/include/boost/unordered/detail/fwd.hpp
+++ b/include/boost/unordered/detail/fwd.hpp
@@ -6,7 +6,7 @@
 #ifndef BOOST_UNORDERED_FWD_HPP_INCLUDED
 #define BOOST_UNORDERED_FWD_HPP_INCLUDED
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif
 
diff --git a/include/boost/unordered/detail/unique.hpp b/include/boost/unordered/detail/unique.hpp
index 81ac053e..cf5062c9 100644
--- a/include/boost/unordered/detail/unique.hpp
+++ b/include/boost/unordered/detail/unique.hpp
@@ -7,7 +7,7 @@
 #ifndef BOOST_UNORDERED_DETAIL_UNIQUE_HPP_INCLUDED
 #define BOOST_UNORDERED_DETAIL_UNIQUE_HPP_INCLUDED
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif
 
diff --git a/include/boost/unordered/detail/util.hpp b/include/boost/unordered/detail/util.hpp
index 570cf8f8..d360e97c 100644
--- a/include/boost/unordered/detail/util.hpp
+++ b/include/boost/unordered/detail/util.hpp
@@ -7,7 +7,7 @@
 #ifndef BOOST_UNORDERED_DETAIL_UTIL_HPP_INCLUDED
 #define BOOST_UNORDERED_DETAIL_UTIL_HPP_INCLUDED
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif
 
diff --git a/include/boost/unordered/unordered_map.hpp b/include/boost/unordered/unordered_map.hpp
index e33dcea2..7eecfbbb 100644
--- a/include/boost/unordered/unordered_map.hpp
+++ b/include/boost/unordered/unordered_map.hpp
@@ -9,7 +9,7 @@
 #ifndef BOOST_UNORDERED_UNORDERED_MAP_HPP_INCLUDED
 #define BOOST_UNORDERED_UNORDERED_MAP_HPP_INCLUDED
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif
 
diff --git a/include/boost/unordered/unordered_map_fwd.hpp b/include/boost/unordered/unordered_map_fwd.hpp
index 980bb3ee..7f7c09bd 100644
--- a/include/boost/unordered/unordered_map_fwd.hpp
+++ b/include/boost/unordered/unordered_map_fwd.hpp
@@ -6,7 +6,7 @@
 #ifndef BOOST_UNORDERED_MAP_FWD_HPP_INCLUDED
 #define BOOST_UNORDERED_MAP_FWD_HPP_INCLUDED
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif
 
diff --git a/include/boost/unordered/unordered_set.hpp b/include/boost/unordered/unordered_set.hpp
index 9ba5002f..73134bfe 100644
--- a/include/boost/unordered/unordered_set.hpp
+++ b/include/boost/unordered/unordered_set.hpp
@@ -9,7 +9,7 @@
 #ifndef BOOST_UNORDERED_UNORDERED_SET_HPP_INCLUDED
 #define BOOST_UNORDERED_UNORDERED_SET_HPP_INCLUDED
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif
 
diff --git a/include/boost/unordered/unordered_set_fwd.hpp b/include/boost/unordered/unordered_set_fwd.hpp
index 0c8b6d8d..2441cb7e 100644
--- a/include/boost/unordered/unordered_set_fwd.hpp
+++ b/include/boost/unordered/unordered_set_fwd.hpp
@@ -6,7 +6,7 @@
 #ifndef BOOST_UNORDERED_SET_FWD_HPP_INCLUDED
 #define BOOST_UNORDERED_SET_FWD_HPP_INCLUDED
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif
 
diff --git a/include/boost/unordered_map.hpp b/include/boost/unordered_map.hpp
index 00d3c91c..ec65f8f5 100644
--- a/include/boost/unordered_map.hpp
+++ b/include/boost/unordered_map.hpp
@@ -9,7 +9,7 @@
 #ifndef BOOST_UNORDERED_MAP_HPP_INCLUDED
 #define BOOST_UNORDERED_MAP_HPP_INCLUDED
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif
 
diff --git a/include/boost/unordered_set.hpp b/include/boost/unordered_set.hpp
index 98c3ce1d..d5b9db0f 100644
--- a/include/boost/unordered_set.hpp
+++ b/include/boost/unordered_set.hpp
@@ -9,7 +9,7 @@
 #ifndef BOOST_UNORDERED_SET_HPP_INCLUDED
 #define BOOST_UNORDERED_SET_HPP_INCLUDED
 
-#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+#if defined(_MSC_VER)
 # pragma once
 #endif