diff --git a/include/boost/regex/v4/regex_workaround.hpp b/include/boost/regex/v4/regex_workaround.hpp
index f245f90d..35eafc25 100644
--- a/include/boost/regex/v4/regex_workaround.hpp
+++ b/include/boost/regex/v4/regex_workaround.hpp
@@ -198,9 +198,10 @@ namespace boost{ namespace BOOST_REGEX_DETAIL_NS{
       const char *strSource 
    )
    {
-      if(std::strlen(strSource)+1 > sizeInBytes)
+	  std::size_t lenSourceWithNull = std::strlen(strSource) + 1;
+	  if (lenSourceWithNull > sizeInBytes)
          return 1;
-      std::strcpy(strDestination, strSource);
+	  std::memcpy(strDestination, strSource, lenSourceWithNull);
       return 0;
    }
    inline std::size_t strcat_s(
@@ -209,9 +210,11 @@ namespace boost{ namespace BOOST_REGEX_DETAIL_NS{
       const char *strSource 
    )
    {
-      if(std::strlen(strSource) + std::strlen(strDestination) + 1 > sizeInBytes)
+	  std::size_t lenSourceWithNull = std::strlen(strSource) + 1;
+	  std::size_t lenDestination = std::strlen(strDestination);
+	  if (lenSourceWithNull + lenDestination > sizeInBytes)
          return 1;
-      std::strcat(strDestination, strSource);
+	  std::memcpy(strDestination + lenDestination, strSource, lenSourceWithNull);
       return 0;
    }