diff --git a/security/pkix/test/lib/pkixtestutil.cpp b/security/pkix/test/lib/pkixtestutil.cpp
old mode 100644
new mode 100755
index 8f365b329b2e..f7190113eda3
--- a/security/pkix/test/lib/pkixtestutil.cpp
+++ b/security/pkix/test/lib/pkixtestutil.cpp
@@ -251,7 +251,7 @@ Integer(long value)
 enum TimeEncoding { UTCTime = 0, GeneralizedTime = 1 };
 
 // Windows doesn't provide gmtime_r, but it provides something very similar.
-#if defined(WIN32) && !defined(_POSIX_THREAD_SAFE_FUNCTIONS)
+#if defined(WIN32) && (!defined(_POSIX_C_SOURCE) || !defined(_POSIX_THREAD_SAFE_FUNCTIONS))
 static tm*
 gmtime_r(const time_t* t, /*out*/ tm* exploded)
 {