diff --git a/About-Apple.cmake b/About-Apple.cmake
index 8ee80bb54..23307b125 100644
--- a/About-Apple.cmake
+++ b/About-Apple.cmake
@@ -1,7 +1,7 @@
 # this will generate a target that will never exist, so it will (should) be executed on each build
 #WARNING: Actually, only Gcc is supported
 
-string (TOUPPER ${CMAKE_BUILD_TYPE} UPPER_CMAKE_BUILD_TYPE)
+string (TOUPPER ${BUILD_TYPE} UPPER_CMAKE_BUILD_TYPE)
 
 set (OUT_FILE "${CMAKE_CURRENT_SOURCE_DIR}/AboutThisBuild.txt")
 set (VERSION_FILE "${CMAKE_CURRENT_SOURCE_DIR}/rtgui/version.h")
diff --git a/About-Linux.cmake b/About-Linux.cmake
index 8ee80bb54..23307b125 100644
--- a/About-Linux.cmake
+++ b/About-Linux.cmake
@@ -1,7 +1,7 @@
 # this will generate a target that will never exist, so it will (should) be executed on each build
 #WARNING: Actually, only Gcc is supported
 
-string (TOUPPER ${CMAKE_BUILD_TYPE} UPPER_CMAKE_BUILD_TYPE)
+string (TOUPPER ${BUILD_TYPE} UPPER_CMAKE_BUILD_TYPE)
 
 set (OUT_FILE "${CMAKE_CURRENT_SOURCE_DIR}/AboutThisBuild.txt")
 set (VERSION_FILE "${CMAKE_CURRENT_SOURCE_DIR}/rtgui/version.h")
diff --git a/About-Windows.cmake b/About-Windows.cmake
index 5f8a5a426..c4b8810ce 100644
--- a/About-Windows.cmake
+++ b/About-Windows.cmake
@@ -1,7 +1,7 @@
 # this will generate a target that will never exist, so it will (should) be executed on each build
 #WARNING: Actually, only Gcc is supported
 
-string (TOUPPER ${CMAKE_BUILD_TYPE} UPPER_CMAKE_BUILD_TYPE)
+string (TOUPPER ${BUILD_TYPE} UPPER_CMAKE_BUILD_TYPE)
 
 set (OUT_FILE "${CMAKE_CURRENT_SOURCE_DIR}/AboutThisBuild.txt")
 set (VERSION_FILE "${CMAKE_CURRENT_SOURCE_DIR}/rtgui/version.h")
diff --git a/CMakeLists.txt b/CMakeLists.txt
index c8ffd5753..4b4af0df5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -146,6 +146,7 @@ elseif (CMAKE_SIZEOF_VOID_P EQUAL 8)
 endif (CMAKE_SIZEOF_VOID_P EQUAL 4)
 
 #generating AboutThisBuild.txt
+set (BUILD_TYPE CMAKE_BUILD_TYPE)
 if (WIN32)
     include (About-Windows.cmake)
 elseif (APPLE)