diff --git a/src/corelib/global/qglobal_p.h b/src/corelib/global/qglobal_p.h
index d52f6268e4..58bc8b7bf3 100644
--- a/src/corelib/global/qglobal_p.h
+++ b/src/corelib/global/qglobal_p.h
@@ -61,6 +61,9 @@
 #endif
 
 #if defined(__cplusplus)
+#ifdef Q_CC_MINGW
+#  include <unistd.h> // Define _POSIX_THREAD_SAFE_FUNCTIONS to obtain localtime_r()
+#endif
 #include <time.h>
 
 QT_BEGIN_NAMESPACE
diff --git a/src/corelib/tools/qdatetime.cpp b/src/corelib/tools/qdatetime.cpp
index 80d6dada60..511dbf0db8 100644
--- a/src/corelib/tools/qdatetime.cpp
+++ b/src/corelib/tools/qdatetime.cpp
@@ -58,6 +58,9 @@
 #endif
 
 #include <cmath>
+#ifdef Q_CC_MINGW
+#  include <unistd.h> // Define _POSIX_THREAD_SAFE_FUNCTIONS to obtain localtime_r()
+#endif
 #include <time.h>
 #ifdef Q_OS_WIN
 #  include <qt_windows.h>