diff --git a/src/cguittfont/irrUString.h b/src/cguittfont/irrUString.h
index eb7abe5a1..5b10e2367 100644
--- a/src/cguittfont/irrUString.h
+++ b/src/cguittfont/irrUString.h
@@ -31,7 +31,7 @@
 #ifndef __IRR_USTRING_H_INCLUDED__
 #define __IRR_USTRING_H_INCLUDED__
 
-#if (__cplusplus > 199711L) || (_MSC_VER >= 1600) || defined(__GXX_EXPERIMENTAL_CXX0X__)
+#if (__cplusplus > 199711L) || (defined(_MSC_VER) && _MSC_VER >= 1600) || defined(__GXX_EXPERIMENTAL_CXX0X__)
 #	define USTRING_CPP0X
 #	if defined(__GXX_EXPERIMENTAL_CXX0X__) && ((__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)))
 #		define USTRING_CPP0X_NEWLITERALS
diff --git a/src/util/cpp11.h b/src/util/cpp11.h
index 14913cb86..17903f2e3 100644
--- a/src/util/cpp11.h
+++ b/src/util/cpp11.h
@@ -20,7 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #ifndef MT_CPP11_HEADER
 #define MT_CPP11_HEADER
 
-#if __cplusplus < 201103L || _MSC_VER < 1600
+#if __cplusplus < 201103L || (defined(_MSC_VER) && _MSC_VER < 1600)
 #define USE_CPP11_FAKE_KEYWORD
 #endif
 
diff --git a/src/util/cpp11_container.h b/src/util/cpp11_container.h
index 0194385fc..a09154071 100644
--- a/src/util/cpp11_container.h
+++ b/src/util/cpp11_container.h
@@ -24,7 +24,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #define USE_UNORDERED_CONTAINERS
 #endif
 
-#if _MSC_VER >= 1600
+#if defined(_MSC_VER) && _MSC_VER >= 1600
 #define USE_UNORDERED_CONTAINERS
 #endif