Index: Makefile.msc
==================================================================
--- Makefile.msc
+++ Makefile.msc
@@ -47,10 +47,13 @@
 # will run on the target platform.  (BCC and TCC are usually the
 # same unless your are cross-compiling.)
 #
 TCC = cl.exe -W3 -DSQLITE_OS_WIN=1 -I. -I$(TOP)\src -fp:precise
 
+# We always have the _msize function available when using MSVC.
+TCC = $(TCC) -DHAVE_MALLOC_USABLE_SIZE -Dmalloc_usable_size=_msize
+
 # The mksqlite3c.tcl and mksqlite3h.tcl scripts will pull in 
 # any extension header files by default.  For non-amalgamation
 # builds, we need to make sure the compiler can find these.
 #
 !IF $(USE_AMALGAMATION)==0