diff --git a/ares/Makefile.dj b/ares/Makefile.dj
index 7f29e2649ec9d9804da3d4d99e54ce0605fe9af5..c146b2126c976c40fb4bcfb1c2bcc05eba6e76a0 100644
--- a/ares/Makefile.dj
+++ b/ares/Makefile.dj
@@ -35,6 +35,11 @@ CFLAGS += -DWATT32 -DHAVE_AF_INET6 -DHAVE_PF_INET6 -DHAVE_IOCTLSOCKET \
 LDFLAGS = -s
 
 ifeq ($(USE_DEBUG),1)
+  CFLAGS += -DDEBUGBUILD
+endif
+
+ifeq ($(USE_CURLDEBUG),1)
+  CFLAGS += -DCURLDEBUG
   EX_LIBS  = ../lib/libcurl.a
   OBJ_HACK = $(OBJECTS)
 else
diff --git a/ares/Makefile.vc6 b/ares/Makefile.vc6
index 14711bda64209c1c79e2218881e2e4dbaca165f3..7fb63d45781e2fbcd562edeca6a3f052bb490828 100644
--- a/ares/Makefile.vc6
+++ b/ares/Makefile.vc6
@@ -35,7 +35,7 @@ EX_LIBS = advapi32.lib ws2_32.lib
 !endif
 
 !if "$(DEBUG_MODEL)" == "d"
-CFLAGS  = $(CFLAGS) -D_DEBUG -GZ
+CFLAGS  = $(CFLAGS) -DDEBUGBUILD -D_DEBUG -GZ
 LDFLAGS = $(LDFLAGS) -debug -fixed:no
 
 !else
diff --git a/ares/vc/acountry/acountry.dsp b/ares/vc/acountry/acountry.dsp
index 9442f507241b529f22d5db8e4aef3cdc147cf3fa..1e0632c1f184c496abd17344e780c81339a4926c 100644
--- a/ares/vc/acountry/acountry.dsp
+++ b/ares/vc/acountry/acountry.dsp
@@ -65,8 +65,8 @@ LINK32=link.exe
 # PROP Intermediate_Dir "Debug"
 # PROP Ignore_Export_Lib 0
 # PROP Target_Dir ""
-# ADD BASE CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
-# ADD CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
+# ADD BASE CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "DEBUGBUILD" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
+# ADD CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "DEBUGBUILD" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
 # ADD BASE RSC /l 0x409 /d "_DEBUG"
 # ADD RSC /l 0x409 /d "_DEBUG"
 BSC32=bscmake.exe
diff --git a/ares/vc/adig/adig.dsp b/ares/vc/adig/adig.dsp
index 757d7bb54169959002e95bf95aa5a272f93b9e2c..3a7545591be4096bd6fec4df6f11d89bd70df4c2 100644
--- a/ares/vc/adig/adig.dsp
+++ b/ares/vc/adig/adig.dsp
@@ -65,8 +65,8 @@ LINK32=link.exe
 # PROP Intermediate_Dir "Debug"
 # PROP Ignore_Export_Lib 0
 # PROP Target_Dir ""
-# ADD BASE CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
-# ADD CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
+# ADD BASE CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "DEBUGBUILD" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
+# ADD CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D /D "DEBUGBUILD" "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
 # ADD BASE RSC /l 0x409 /d "_DEBUG"
 # ADD RSC /l 0x409 /d "_DEBUG"
 BSC32=bscmake.exe
diff --git a/ares/vc/ahost/ahost.dsp b/ares/vc/ahost/ahost.dsp
index 914eb6e4d5f66bb31adff5ea79fdb05edf2811db..bfadce2b0ef3245b055fed72286f209726ca497e 100644
--- a/ares/vc/ahost/ahost.dsp
+++ b/ares/vc/ahost/ahost.dsp
@@ -65,8 +65,8 @@ LINK32=link.exe
 # PROP Intermediate_Dir "Debug"
 # PROP Ignore_Export_Lib 0
 # PROP Target_Dir ""
-# ADD BASE CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
-# ADD CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
+# ADD BASE CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "DEBUGBUILD" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
+# ADD CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "DEBUGBUILD" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /FD /GZ /c
 # ADD BASE RSC /l 0x409 /d "_DEBUG"
 # ADD RSC /l 0x409 /d "_DEBUG"
 BSC32=bscmake.exe
diff --git a/ares/vc/areslib/areslib.dsp b/ares/vc/areslib/areslib.dsp
index 8a8624bd9dc2714ecf0f796348b9b4a46071c50c..ce84fb9fab6e374d2914f15e0e0372634b942578 100644
--- a/ares/vc/areslib/areslib.dsp
+++ b/ares/vc/areslib/areslib.dsp
@@ -63,8 +63,8 @@ LIB32=link.exe -lib
 # PROP Output_Dir "Debug"
 # PROP Intermediate_Dir "Debug"
 # PROP Target_Dir ""
-# ADD BASE CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "_DEBUG" /D "_MBCS" /D "_LIB" /FD /GZ /c
-# ADD CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "_DEBUG" /D "_MBCS" /D "_LIB" /FD /GZ /c
+# ADD BASE CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "DEBUGBUILD" /D "_DEBUG" /D "_MBCS" /D "_LIB" /FD /GZ /c
+# ADD CPP /nologo /MDd /W3 /Gm /GX /ZI /Od /I "..\.." /D "WIN32" /D "DEBUGBUILD" /D "_DEBUG" /D "_MBCS" /D "_LIB" /FD /GZ /c
 # ADD BASE RSC /l 0x409 /d "_DEBUG"
 # ADD RSC /l 0x409 /d "_DEBUG"
 BSC32=bscmake.exe