diff --git a/include/internal/catch_output_redirect.cpp b/include/internal/catch_output_redirect.cpp
index 1308bfe3..6928d160 100644
--- a/include/internal/catch_output_redirect.cpp
+++ b/include/internal/catch_output_redirect.cpp
@@ -66,7 +66,7 @@ namespace Catch {
         if (tmpnam_s(m_buffer)) {
             CATCH_RUNTIME_ERROR("Could not get a temp filename");
         }
-        if (fopen_s(&m_file, m_buffer, "w")) {
+        if (fopen_s(&m_file, m_buffer, "w+")) {
             char buffer[100];
             if (strerror_s(buffer, errno)) {
                 CATCH_RUNTIME_ERROR("Could not translate errno to a string");