diff --git a/src/3rdparty/javascriptcore/JavaScriptCore/JavaScriptCore.pri b/src/3rdparty/javascriptcore/JavaScriptCore/JavaScriptCore.pri
index 2298de3913d814e4018c6d652ef019049ea24158..6ee0aed25b309040376f07ab22de87c433be4b58 100644
--- a/src/3rdparty/javascriptcore/JavaScriptCore/JavaScriptCore.pri
+++ b/src/3rdparty/javascriptcore/JavaScriptCore/JavaScriptCore.pri
@@ -41,6 +41,8 @@ DEFINES += BUILDING_QT__ BUILDING_JavaScriptCore BUILDING_WTF
 win32-* {
 #   Prevent definition of min, max macros in windows.h
     DEFINES+=NOMINMAX
+#   Enables rand_s
+    msvc: DEFINES += _CRT_RAND_S
     LIBS_PRIVATE += -lwinmm
 }
 contains(JAVASCRIPTCORE_JIT,yes) {