diff --git a/src/makevc.env b/src/makevc.env
index 0082db93dc..2cae086a8c 100644
--- a/src/makevc.env
+++ b/src/makevc.env
@@ -150,14 +150,18 @@ OPT = /Od /Gy
 # ***N.B.*** to save space/time, comment out /FR to avoid browse info (.sbr files) being generated
 DEBUG_FLAGS= /Zi /D__WXDEBUG__ # /DDEBUG=1 # /FR
 LINK_DEBUG_FLAGS=-debug:full -debugtype:cv # /PDB:NONE
-CRTFLAG=/MDd
+_CRTFLAG=/MDd
 !else
 # /O1 - smallest code
 # /O2 - fastest code
 OPT = /O1 # /O2 # /Od
 DEBUG_FLAGS=
 LINK_DEBUG_FLAGS=/RELEASE
-CRTFLAG=/MD
+_CRTFLAG=/MD
+!endif
+
+!if "$(CRTFLAG)" == ""
+CRTFLAG=$(_CRTFLAG)
 !endif
 
 !if "$(DLL)" == "0"