diff --git a/bacnet-stack/ports/rtos32/makefile.mak b/bacnet-stack/ports/rtos32/makefile.mak
index f816b787..6d74ea1b 100644
--- a/bacnet-stack/ports/rtos32/makefile.mak
+++ b/bacnet-stack/ports/rtos32/makefile.mak
@@ -53,7 +53,7 @@ LOCATE = $(RTOS32_DIR)\bin\rtloc
 CC_DIR     = $(BORLAND_DIR)\BIN
 CC_INCLDIR = $(BORLAND_DIR)\include
 INCL_DIRS = -I$(BORLAND_DIR)\include;$(RTOS32_DIR)\include;../../;
-DEFINES = -DDOC
+DEFINES = -DDOC;BACDL_BIP=1
 
 CFLAGS = $(INCL_DIRS) $(CS_FLAGS) $(DEFINES)