diff --git a/Release/include/cpprest/filestream.h b/Release/include/cpprest/filestream.h
index 1e4a0f278e..511519a7de 100644
--- a/Release/include/cpprest/filestream.h
+++ b/Release/include/cpprest/filestream.h
@@ -715,7 +715,7 @@ class basic_file_buffer : public details::streambuf_state_manager<_CharType>
         const utility::string_t& _Filename,
         std::ios_base::openmode _Mode = std::ios_base::out,
 #ifdef _WIN32
-        int _Prot = (int)std::ios_base::_Openprot
+        int _Prot = _SH_DENYNO
 #else
         int _Prot = 0                                         // unsupported on Linux, for now
 #endif
@@ -1012,7 +1012,7 @@ class file_stream
     static pplx::task<streams::basic_istream<_CharType>> open_istream(const utility::string_t& file_name,
                                                                       std::ios_base::openmode mode = std::ios_base::in,
 #ifdef _WIN32
-                                                                      int prot = (int)std::ios_base::_Openprot
+                                                                      int prot = _SH_DENYNO
 #else
                                                                       int prot = 0
 #endif
@@ -1037,7 +1037,7 @@ class file_stream
     static pplx::task<streams::basic_ostream<_CharType>> open_ostream(const utility::string_t& file_name,
                                                                       std::ios_base::openmode mode = std::ios_base::out,
 #ifdef _WIN32
-                                                                      int prot = (int)std::ios_base::_Openprot
+                                                                      int prot = _SH_DENYNO
 #else
                                                                       int prot = 0
 #endif
diff --git a/Release/tests/functional/streams/fstreambuf_tests.cpp b/Release/tests/functional/streams/fstreambuf_tests.cpp
index 190eb66b0c..bd63633091 100644
--- a/Release/tests/functional/streams/fstreambuf_tests.cpp
+++ b/Release/tests/functional/streams/fstreambuf_tests.cpp
@@ -19,7 +19,7 @@ using namespace Windows::Storage;
 #endif
 
 #ifdef _WIN32
-#define DEFAULT_PROT (int)std::ios_base::_Openprot
+#define DEFAULT_PROT _SH_DENYNO
 #else
 #define DEFAULT_PROT 0
 #define _SH_DENYRW 0x20
diff --git a/Release/tests/functional/streams/istream_tests.cpp b/Release/tests/functional/streams/istream_tests.cpp
index 32cb545aa2..9feed549ea 100644
--- a/Release/tests/functional/streams/istream_tests.cpp
+++ b/Release/tests/functional/streams/istream_tests.cpp
@@ -22,7 +22,7 @@ using namespace Windows::Storage;
 #endif
 
 #ifdef _WIN32
-#define DEFAULT_PROT (int)std::ios_base::_Openprot
+#define DEFAULT_PROT _SH_DENYNO
 #else
 #define DEFAULT_PROT 0
 #endif
diff --git a/Release/tests/functional/streams/stdstream_tests.cpp b/Release/tests/functional/streams/stdstream_tests.cpp
index 34b9b3af12..4072224e05 100644
--- a/Release/tests/functional/streams/stdstream_tests.cpp
+++ b/Release/tests/functional/streams/stdstream_tests.cpp
@@ -23,7 +23,7 @@ using namespace Windows::Storage;
 #endif
 
 #ifdef _WIN32
-#define DEFAULT_PROT (int)std::ios_base::_Openprot
+#define DEFAULT_PROT _SH_DENYNO
 #else
 #define DEFAULT_PROT 0
 #endif