diff --git a/code/nel/CMakeModules/nel.cmake b/code/nel/CMakeModules/nel.cmake
index c58b5a1a0..2f41e5d77 100644
--- a/code/nel/CMakeModules/nel.cmake
+++ b/code/nel/CMakeModules/nel.cmake
@@ -226,12 +226,25 @@ MACRO(NL_SETUP_BUILD)
   ENDIF(CMAKE_BUILD_TYPE MATCHES "Debug")
 
   IF(WIN32)
-    SET(NL_DEBUG_CFLAGS "/EHa /Ob1 /Zi")
-    SET(NL_RELEASE_CFLAGS "/EHa /Zi /Ox /Ob2 /Oi /Ot /Oy /GT /GF /GS-")
-    SET(NL_RELEASEDEBUG_CFLAGS "/EHa /DNL_RELEASE_DEBUG /Zi /Ob2 /GF")
+    # don't use a /O[012x] flag if you want custom optimizations
+    SET(SPEED_OPTIMIZATIONS "/Ob2 /Oi /Ot /Oy /GT /GF /GS-")
+    SET(SIZE_OPTIMIZATIONS "/O1")
+    # without inlining it's unusable, use custom optimizations again
+    SET(MIN_OPTIMIZATIONS "/Ob1")
+
+    SET(CMAKE_C_FLAGS_DEBUG "/MDd /Zi /RTC1 /D_DEBUG ${MIN_OPTIMIZATIONS}")
+    SET(CMAKE_C_FLAGS_RELEASE "/MD /Zi /D NDEBUG ${SPEED_OPTIMIZATIONS}")
+    SET(CMAKE_C_FLAGS_RELWITHDEBINFO "/MD /Zi /D NDEBUG ${SPEED_OPTIMIZATIONS}")
+    SET(CMAKE_C_FLAGS_MINSIZEREL "/MD /D NDEBUG ${SIZE_OPTIMIZATIONS}")
+    SET(CMAKE_CXX_FLAGS_DEBUG ${CMAKE_C_FLAGS_DEBUG})
+    SET(CMAKE_CXX_FLAGS_RELEASE ${CMAKE_C_FLAGS_RELEASE})
+    SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO ${CMAKE_C_FLAGS_RELWITHDEBINFO})
+    SET(CMAKE_CXX_FLAGS_MINSIZEREL ${CMAKE_C_FLAGS_MINSIZEREL})
+
+    SET(NL_DEBUG_CFLAGS "/EHa /Zi")
+    SET(NL_RELEASE_CFLAGS "/EHa /Zi")
     SET(NL_DEBUG_LINK_FLAGS "/NODEFAULTLIB:msvcrt")
     SET(NL_RELEASE_LINK_FLAGS "/OPT:REF /OPT:ICF")
-    SET(NL_RELEASEDEBUG_LINK_FLAGS "/OPT:REF /OPT:ICF")
   ELSE(WIN32)
     SET(PLATFORM_CFLAGS "-ftemplate-depth-24 -D_REENTRANT -Wall -ansi -W -Wpointer-arith -Wsign-compare -Wno-deprecated-declarations -Wno-multichar -Wno-long-long -Wno-unused")
     IF(WITH_COVERAGE)
@@ -243,7 +256,6 @@ MACRO(NL_SETUP_BUILD)
     ENDIF(NOT APPLE)
     SET(NL_DEBUG_CFLAGS "-DNL_DEBUG -g")
     SET(NL_RELEASE_CFLAGS "-DNL_RELEASE -O6 -g")
-    SET(NL_RELEASEDEBUG_CFLAGS "-DNL_RELEASE_DEBUG -g -finline-functions -O3 ")
     SET(NL_NONE_CFLAGS "-DNL_RELEASE -g -finline-functions -O2 ")
   ENDIF(WIN32)
 
@@ -286,14 +298,14 @@ MACRO(NL_SETUP_BUILD_FLAGS)
   SET(CMAKE_LINK_FLAGS_RELEASE "${CMAKE_LINK_FLAGS_RELEASE} ${NL_RELEASE_LINK_FLAGS} ${PLATFORM_LINKFLAGS} ")
 
   ## RelWithDebInfo
-  SET(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO} ${NL_RELEASEDEBUG_CFLAGS} ${PLATFORM_CFLAGS} ")
-  SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} ${NL_RELEASEDEBUG_CFLAGS} ${PLATFORM_CFLAGS} ")
-  SET(CMAKE_LINK_FLAGS_RELWITHDEBINFO "${CMAKE_LINK_FLAGS_RELWITHDEBINFO} ${NL_RELEASEDEBUG_LINK_FLAGS} ${PLATFORM_LINKFLAGS} ")
+  SET(CMAKE_C_FLAGS_RELWITHDEBINFO "${CMAKE_C_FLAGS_RELWITHDEBINFO} ${NL_RELEASE_CFLAGS} ${PLATFORM_CFLAGS} ")
+  SET(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} ${NL_RELEASE_CFLAGS} ${PLATFORM_CFLAGS} ")
+  SET(CMAKE_LINK_FLAGS_RELWITHDEBINFO "${CMAKE_LINK_FLAGS_RELWITHDEBINFO} ${NL_RELEASE_LINK_FLAGS} ${PLATFORM_LINKFLAGS} ")
 
   ## MinSizeRel
-  SET(CMAKE_C_FLAGS_MINSIZEREL "${CMAKE_C_FLAGS_MINSIZEREL} ${NL_RELEASEDEBUG_CFLAGS} ${PLATFORM_CFLAGS} ")
-  SET(CMAKE_CXX_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS_MINSIZEREL} ${NL_RELEASEDEBUG_CFLAGS} ${PLATFORM_CFLAGS} ")
-  SET(CMAKE_LINK_FLAGS_MINSIZEREL "${CMAKE_LINK_FLAGS_MINSIZEREL} ${NL_RELEASEDEBUG_LINK_CFLAGS} ${PLATFORM_LINKFLAGS} ")
+  SET(CMAKE_C_FLAGS_MINSIZEREL "${CMAKE_C_FLAGS_MINSIZEREL} ${NL_RELEASE_CFLAGS} ${PLATFORM_CFLAGS} ")
+  SET(CMAKE_CXX_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS_MINSIZEREL} ${NL_RELEASE_CFLAGS} ${PLATFORM_CFLAGS} ")
+  SET(CMAKE_LINK_FLAGS_MINSIZEREL "${CMAKE_LINK_FLAGS_MINSIZEREL} ${NL_RELEASE_LINK_CFLAGS} ${PLATFORM_LINKFLAGS} ")
 ENDMACRO(NL_SETUP_BUILD_FLAGS)
 
 MACRO(NL_SETUP_PREFIX_PATHS)