Build Issue : undefined symbol: _heap

[dennowiggle]

I get the following error when trying to build with the latest z88dk. This is the error for "make ifconfig"

zcc  +cpm -create-app -pragma-include:zpragma.inc -DAMALLOC2 -oifconfig -Wunused addrprint.o w5500.o dhcp.o spi.o socket.o ethernet.o dns.o libhost.o libinet.o
alloc/malloc-classic/calloc_callee.asm:27: error: undefined symbol: _heap
  ^---- _heap
alloc/malloc-classic/free.asm:25: error: undefined symbol: _heap
  ^---- _heap
make: *** [Makefile:56: ifconfig] Error 1

Any suggestions on how to address this.