diff --git a/Makefile b/Makefile
index 9219390fbf0c2155e83bcd109ae9f6dacb1d4d92..93666f69198ebc81ccffe50d40b194237a576bf1 100644
--- a/Makefile
+++ b/Makefile
@@ -59,9 +59,6 @@ OVERWRITE=y
 # Include debug and macro symbols in the executables (-g) and profiling info (-pg)
 DEBUG=-g3
 
-# Asterisk SMDI integration
-WITH_SMDI=1
-
 # Staging directory
 # Files are copied here temporarily during the install process
 # For example, make DESTDIR=/tmp/asterisk woud put things in
@@ -365,7 +362,7 @@ ifeq ($(OSARCH),SunOS)
 endif
 
 ifeq ($(MAKETOPLEVEL),$(MAKELEVEL))
-  CFLAGS+=$(TOPDIR_CFLAGS) $(ASTCFLAGS)
+  CFLAGS+=$(TOPDIR_CFLAGS)$(ASTCFLAGS)
 endif
 
 # This is used when generating the doxygen documentation
@@ -487,7 +484,7 @@ include/asterisk/buildopts.h: menuselect.makeopts
 	@rm -f $@.tmp
 
 stdtime/libtime.a:
-	CFLAGS="$(MOD_SUBDIR_CFLAGS) $(ASTCFLAGS)" $(MAKE) -C stdtime libtime.a
+	CFLAGS="$(MOD_SUBDIR_CFLAGS)$(ASTCFLAGS)" $(MAKE) -C stdtime libtime.a
 
 asterisk: include/asterisk/buildopts.h editline/libedit.a db1-ast/libdb1.a stdtime/libtime.a $(OBJS)
 	build_tools/make_build_h > include/asterisk/build.h.tmp
@@ -502,9 +499,9 @@ muted: muted.o
 	$(CC) $(AUDIO_LIBS) -o muted muted.o
 
 subdirs: 
-	@for x in $(MOD_SUBDIRS); do CFLAGS="$(MOD_SUBDIR_CFLAGS) $(ASTCFLAGS)" $(MAKE) -C $$x || exit 1 ; done
-	@CFLAGS="$(OTHER_SUBDIR_CFLAGS) $(ASTCFLAGS)" $(MAKE) -C utils
-	@CFLAGS="$(OTHER_SUBDIR_CFLAGS) $(ASTCFLAGS)" $(MAKE) -C agi
+	@for x in $(MOD_SUBDIRS); do CFLAGS="$(MOD_SUBDIR_CFLAGS)$(ASTCFLAGS)" $(MAKE) -C $$x || exit 1 ; done
+	@CFLAGS="$(OTHER_SUBDIR_CFLAGS)$(ASTCFLAGS)" $(MAKE) -C utils
+	@CFLAGS="$(OTHER_SUBDIR_CFLAGS)$(ASTCFLAGS)" $(MAKE) -C agi
 
 clean-depend:
 	@for x in $(SUBDIRS); do $(MAKE) -C $$x clean-depend || exit 1 ; done
diff --git a/apps/Makefile b/apps/Makefile
index 7b79281bc02847021326e348a323b1dd8bc1b208..ed26d855f8fd4ffd9e304af6b04b888f4c3c2e84 100644
--- a/apps/Makefile
+++ b/apps/Makefile
@@ -13,10 +13,6 @@
 
 MODS:=$(filter-out $(MENUSELECT_APPS),$(patsubst %.c,%.so,$(wildcard app_*.c)))
 
-ifneq ($(WITH_SMDI),)
-  CFLAGS+=-DWITH_SMDI
-endif
-
 # If you have UnixODBC you can use ODBC voicemail
 # storage
 #
diff --git a/build_tools/cflags.xml b/build_tools/cflags.xml
index 03fd36991d2c0c4554bd60cb4ffe0813829085ef..c15ca1c42affc993cad6f59fa74c70f228d6e335 100644
--- a/build_tools/cflags.xml
+++ b/build_tools/cflags.xml
@@ -11,10 +11,13 @@
 		</member>
 		<member name="MALLOC_DEBUG" displayname="Keep Track of Memory Allocations">
 		</member>
+		<member name="MTX_PROFILE" displayname="Enable Code Profiling Using TSC Counters">
+		</member>
 		<member name="RADIO_RELAX" displayname="Relax DTMF for Radio Applications">
 		</member>
 		<member name="TRACE_FRAMES" displayname="Trace Frame Allocations">
 		</member>
-		<member name="MTX_PROFILE" displayname="Enable Code Profiling Using TSC Counters">
+		<member name="WITH_SMDI" displayname="Include SMDI Support">
+			<defaultenabled>yes</defaultenabled>
 		</member>
 	</category>
diff --git a/channels/Makefile b/channels/Makefile
index 0b4ddacc3ff75c630918773a5139ed9ce5dd21af..b68c0649f7638347cbc35361654f8f933d5db947 100644
--- a/channels/Makefile
+++ b/channels/Makefile
@@ -44,10 +44,6 @@ ifeq ($(OSARCH),SunOS)
   SOLINK+=-lrt
 endif
 
-ifeq ($(WITH_SMDI),1)
-  CFLAGS+=-DWITH_SMDI
-endif
-
 ifeq ($(wildcard h323/libchanh323.a),)
   MODS:=$(filter-out chan_h323.so,$(MODS))
 endif