diff --git a/configure.ac b/configure.ac
index 65227ab915..6a762a68f9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -291,10 +291,6 @@ char * strerror(int n);
 
 // TR1 regex not supported in GCC <= 4.5
 #ifndef LYX_USE_TR1
-#  if defined(_MSC_VER) && (_MSC_VER >= 1600)
-#    define LYX_USE_TR1
-#    define LYX_USE_TR1_REGEX
-#  endif
 #  if __GNUC__ == 4 && __GNUC_MINOR__ >= 4
 #    define LYX_USE_TR1
 #  endif