diff --git a/googletest/src/gtest-port.cc b/googletest/src/gtest-port.cc
index 91f285c6..aa98ddb1 100644
--- a/googletest/src/gtest-port.cc
+++ b/googletest/src/gtest-port.cc
@@ -41,6 +41,9 @@
 # include <io.h>
 # include <sys/stat.h>
 # include <map>  // Used in ThreadLocal.
+# ifdef _MSC_VER
+#  include <crtdbg.h>
+# endif  // _MSC_VER
 #else
 # include <unistd.h>
 #endif  // GTEST_OS_WINDOWS