diff --git a/irr/src/CMakeLists.txt b/irr/src/CMakeLists.txt
index 2bc935b9f..161a0c060 100644
--- a/irr/src/CMakeLists.txt
+++ b/irr/src/CMakeLists.txt
@@ -83,6 +83,10 @@ if(LINUX_PLATFORM)
 	add_definitions(-D_IRR_LINUX_PLATFORM_)
 endif()
 
+if(MSVC)
+	add_definitions(-D_CRT_SECURE_NO_WARNINGS)
+endif()
+
 if(USE_SDL2)
 	set(DEVICE "SDL")
 elseif(DEVICE STREQUAL "SDL")
diff --git a/lib/lua/CMakeLists.txt b/lib/lua/CMakeLists.txt
index 2de4840cb..869a3c320 100644
--- a/lib/lua/CMakeLists.txt
+++ b/lib/lua/CMakeLists.txt
@@ -22,6 +22,10 @@ else()
 	set(DEFAULT_ANSI TRUE)
 endif()
 
+if(MSVC)
+	set(COMMON_CFLAGS "${COMMON_CFLAGS} -D_CRT_SECURE_NO_WARNINGS")
+endif()
+
 if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
 	set(COMMON_LDFLAGS "${COMMON_LDFLAGS} -Wl,-E -lm")
 	set(DEFAULT_DLOPEN ON)
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 955bf05f2..0ea8a40a9 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -781,7 +781,7 @@ endif()
 
 if(MSVC)
 	# Visual Studio
-	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /D _WIN32_WINNT=0x0601 /D WIN32_LEAN_AND_MEAN")
+	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /D _WIN32_WINNT=0x0601 /D WIN32_LEAN_AND_MEAN /D _CRT_SECURE_NO_WARNINGS")
 	# EHa enables SEH exceptions (used for catching segfaults)
 	set(CMAKE_CXX_FLAGS_RELEASE "/EHa /Ox /MD /GS- /Zi /fp:fast /D NDEBUG /D _HAS_ITERATOR_DEBUGGING=0")
 	if(CMAKE_SIZEOF_VOID_P EQUAL 4)