diff --git a/dtool/pptempl/Global.pp b/dtool/pptempl/Global.pp
index 7c6ce5eff6..50ec91648f 100644
--- a/dtool/pptempl/Global.pp
+++ b/dtool/pptempl/Global.pp
@@ -337,13 +337,21 @@
 #defer get_igatemscan \
   $[if $[and $[run_interrogate],$[components $[IGATESCAN],$[active_component_libs]]], \
     $[TARGET]]
+
+// This variable returns the set of external packages used by this
+// target, and by all the components shared by this target.
+#defer use_packages $[sort $[USE_PACKAGES] $[components $[USE_PACKAGES],$[active_component_libs]]]
     
 // This function returns the appropriate cflags for the target, based
 // on the various external packages this particular target claims to
 // require.
 #defun get_cflags
   #define alt_cflags $[stl_cflags] $[nspr_cflags] $[python_cflags]
-  
+
+  #foreach package $[use_packages]
+    #set alt_cflags $[alt_cflags] $[$[package]_cflags]
+  #end package
+
   #if $[ne $[USE_CRYPTO] $[components $[USE_CRYPTO],$[active_component_libs]],]
     #set alt_cflags $[alt_cflags] $[crypto_cflags]
   #endif
@@ -418,6 +426,10 @@
 #defun get_ipath
   #define alt_ipath $[stl_ipath] $[nspr_ipath] $[python_ipath]
   
+  #foreach package $[use_packages]
+    #set alt_ipath $[alt_ipath] $[$[package]_ipath]
+  #end package
+
   #if $[ne $[USE_CRYPTO] $[components $[USE_CRYPTO],$[active_component_libs]],]
     #set alt_ipath $[alt_ipath] $[crypto_ipath]
   #endif
@@ -491,6 +503,10 @@
 // directory names only; the -L switch is not included here.
 #defun get_lpath
   #define alt_lpath $[stl_lpath] $[nspr_lpath] $[python_lpath]
+
+  #foreach package $[use_packages]
+    #set alt_lpath $[alt_lpath] $[$[package]_lpath]
+  #end package
   
   #if $[WINDOWS_PLATFORM]  
     #set alt_lpath $[WIN32_PLATFORMSDK_LIBPATH] $[alt_lpath] 
@@ -569,6 +585,10 @@
 // included here.
 #defun get_libs
   #define alt_libs $[stl_libs] $[nspr_libs] $[python_libs] $[TARGET_LIBS]
+
+  #foreach package $[use_packages]
+    #set alt_libs $[alt_libs] $[$[package]_libs]
+  #end package
   
   #if $[ne $[USE_CRYPTO] $[components $[USE_CRYPTO],$[active_component_libs] $[transitive_link]],]
     #set alt_libs $[alt_libs] $[crypto_libs]
@@ -645,7 +665,7 @@
 
 // This function returns the appropriate value for ld for the target.
 #defun get_ld
-  #if $[ne $[USE_MAYA] $[components $[USE_MAYA],$[COMPONENT_LD]],]
+  #if $[filter maya,$[use_packages]]
     $[maya_ld]
   #endif
 #end get_ld
diff --git a/panda/metalibs/panda/Sources.pp b/panda/metalibs/panda/Sources.pp
index 3a3e7e31bb..a1d6f589f2 100644
--- a/panda/metalibs/panda/Sources.pp
+++ b/panda/metalibs/panda/Sources.pp
@@ -6,7 +6,7 @@
 
 #define DIR_TYPE metalib
 #define BUILDING_DLL BUILDING_PANDA
-#define USE_NET yes
+#define USE_PACKAGES net
 
 #define COMPONENT_LIBS \
     pgraph \
diff --git a/panda/metalibs/pandacr/Sources.pp b/panda/metalibs/pandacr/Sources.pp
index 3e4fd20ce4..66d63bbd25 100644
--- a/panda/metalibs/pandacr/Sources.pp
+++ b/panda/metalibs/pandacr/Sources.pp
@@ -8,8 +8,6 @@
 #define BUILDING_DLL BUILDING_PANDACR
 #define BUILD_DIRECTORY $[HAVE_CHROMIUM]
 
-//#define USE_CHROMIUM yes
-
 #define COMPONENT_LIBS \
     crgsg wcrdisplay
 
diff --git a/panda/metalibs/pandaexpress/Sources.pp b/panda/metalibs/pandaexpress/Sources.pp
index 42e1a24cfd..61ee6d6681 100644
--- a/panda/metalibs/pandaexpress/Sources.pp
+++ b/panda/metalibs/pandaexpress/Sources.pp
@@ -6,7 +6,7 @@
 
 #define DIR_TYPE metalib
 #define BUILDING_DLL BUILDING_PANDAEXPRESS
-#define USE_NET yes
+#define USE_PACKAGES net
 
 #define COMPONENT_LIBS downloader event ipc express pandabase
 #define OTHER_LIBS dtoolconfig dtool
diff --git a/panda/src/audiotraits/Sources.pp b/panda/src/audiotraits/Sources.pp
index 49905c7530..2f3beead46 100644
--- a/panda/src/audiotraits/Sources.pp
+++ b/panda/src/audiotraits/Sources.pp
@@ -4,7 +4,7 @@
 #begin lib_target
   #define TARGET miles_audio
   #define BUILD_TARGET $[HAVE_RAD_MSS]
-  #define USE_RAD_MSS yes
+  #define USE_PACKAGES rad_mss
   #define BUILDING_DLL BUILDING_MILES_AUDIO
   #define LOCAL_LIBS audio
   #define WIN_SYS_LIBS $[WIN_SYS_LIBS] user32.lib advapi32.lib
diff --git a/panda/src/crgsg/Sources.pp b/panda/src/crgsg/Sources.pp
index 2b3fd52d9f..e27237548d 100644
--- a/panda/src/crgsg/Sources.pp
+++ b/panda/src/crgsg/Sources.pp
@@ -2,7 +2,7 @@
 
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
-#define USE_CHROMIUM yes
+#define USE_PACKAGES chromium
 
 #begin lib_target
   #define TARGET crgsg
diff --git a/panda/src/downloader/Sources.pp b/panda/src/downloader/Sources.pp
index 5eadaefc0d..e8228c7690 100644
--- a/panda/src/downloader/Sources.pp
+++ b/panda/src/downloader/Sources.pp
@@ -1,13 +1,11 @@
 #define LOCAL_LIBS event ipc express pandabase
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
-#define USE_ZLIB yes
-#define USE_IPC yes
-#define USE_NET yes
+#define USE_PACKAGES zlib ipc net
 
 #begin lib_target
   #define TARGET downloader
-  
+
   #define COMBINED_SOURCES $[TARGET]_composite1.cxx \
     $[if $[HAVE_NET], $[TARGET]_composite3.cxx] \
     $[if $[HAVE_ZLIB], $[TARGET]_composite4.cxx] \
diff --git a/panda/src/downloadertools/Sources.pp b/panda/src/downloadertools/Sources.pp
index 6878ac0073..fd29a670d4 100644
--- a/panda/src/downloadertools/Sources.pp
+++ b/panda/src/downloadertools/Sources.pp
@@ -1,8 +1,8 @@
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m pystub
 #define LOCAL_LIBS downloader express event ipc
-#define USE_IPC yes
 #define BUILD_DIRECTORY $[HAVE_IPC]
+#define USE_PACKAGES ipc
 
 #begin bin_target
   #define TARGET apply_patch
@@ -27,7 +27,7 @@
 #begin bin_target
   #define TARGET check_adler
   #define BUILD_TARGET $[HAVE_ZLIB]
-  #define USE_ZLIB yes
+  #define USE_PACKAGES $[USE_PACKAGES] zlib
 
   #define SOURCES \
     check_adler.cxx
@@ -37,7 +37,7 @@
 #begin bin_target
   #define TARGET check_crc
   #define BUILD_TARGET $[HAVE_ZLIB]
-  #define USE_ZLIB yes
+  #define USE_PACKAGES $[USE_PACKAGES] zlib
 
   #define SOURCES \
     check_crc.cxx
@@ -47,7 +47,7 @@
 #begin bin_target
   #define TARGET check_md5
   #define BUILD_TARGET $[HAVE_CRYPTO]
-  #define USE_CRYPTO yes
+  #define USE_PACKAGES $[USE_PACKAGES] crypto
 
   #define SOURCES \
     check_md5.cxx
@@ -65,7 +65,7 @@
 #begin bin_target
   #define TARGET pcompress
   #define BUILD_TARGET $[HAVE_ZLIB]
-  #define USE_ZLIB yes
+  #define USE_PACKAGES $[USE_PACKAGES] zlib
 
   #define SOURCES \
     pcompress.cxx
@@ -75,7 +75,7 @@
 #begin bin_target
   #define TARGET pdecompress
   #define BUILD_TARGET $[HAVE_ZLIB]
-  #define USE_ZLIB yes
+  #define USE_PACKAGES $[USE_PACKAGES] zlib
 
   #define SOURCES \
     pdecompress.cxx
@@ -85,7 +85,7 @@
 #begin bin_target
   #define TARGET test_downloader
   #define BUILD_TARGET $[HAVE_ZLIB]
-  #define USE_ZLIB yes
+  #define USE_PACKAGES $[USE_PACKAGES] zlib
 
   #define SOURCES \
     test_downloader.cxx
diff --git a/panda/src/dxgsg/Sources.pp b/panda/src/dxgsg/Sources.pp
index b4a1102655..fd7f77a34e 100644
--- a/panda/src/dxgsg/Sources.pp
+++ b/panda/src/dxgsg/Sources.pp
@@ -2,7 +2,7 @@
 
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
-#define USE_DX yes
+#define USE_PACKAGES dx
 
 #begin lib_target
 
diff --git a/panda/src/dxgsg8/Sources.pp b/panda/src/dxgsg8/Sources.pp
index 587cccc8e9..dcea0faeb8 100644
--- a/panda/src/dxgsg8/Sources.pp
+++ b/panda/src/dxgsg8/Sources.pp
@@ -2,7 +2,7 @@
 
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
-#define USE_DX yes
+#define USE_PACKAGES dx
 
 #begin lib_target
   #define TARGET dxgsg8
diff --git a/panda/src/egg2pg/Sources.pp b/panda/src/egg2pg/Sources.pp
index 9a48c7a140..75378f0033 100644
--- a/panda/src/egg2pg/Sources.pp
+++ b/panda/src/egg2pg/Sources.pp
@@ -1,7 +1,7 @@
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
 
-#define USE_NURBSPP yes
+#define USE_PACKAGES nurbspp
 
 #begin lib_target
   #define TARGET egg2pg
diff --git a/panda/src/express/Sources.pp b/panda/src/express/Sources.pp
index 095d10796f..8e5aa45dcc 100644
--- a/panda/src/express/Sources.pp
+++ b/panda/src/express/Sources.pp
@@ -4,9 +4,7 @@
 
 #begin lib_target
   #define TARGET express
-  #define USE_NSPR yes
-  #define USE_CRYPTO yes
-  #define USE_NET yes
+  #define USE_PACKAGES nspr crypto net
   
   #define COMBINED_SOURCES $[TARGET]_composite1.cxx $[TARGET]_composite2.cxx
 
diff --git a/panda/src/glgsg/Sources.pp b/panda/src/glgsg/Sources.pp
index c17c871be1..8deaf67e6f 100644
--- a/panda/src/glgsg/Sources.pp
+++ b/panda/src/glgsg/Sources.pp
@@ -2,7 +2,7 @@
 
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
-#define USE_GL yes
+#define USE_PACKAGES gl
 
 #begin lib_target
   #define TARGET glgsg
diff --git a/panda/src/glutdisplay/Sources.pp b/panda/src/glutdisplay/Sources.pp
index b5f1da9dfb..ba3e3a7983 100644
--- a/panda/src/glutdisplay/Sources.pp
+++ b/panda/src/glutdisplay/Sources.pp
@@ -2,8 +2,7 @@
 
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
-#define USE_GL yes
-#define USE_GLUT yes
+#define USE_PACKAGES gl glut
 
 #begin lib_target
   #define TARGET glutdisplay
diff --git a/panda/src/glxdisplay/Sources.pp b/panda/src/glxdisplay/Sources.pp
index a08f7707d0..adca876c9e 100644
--- a/panda/src/glxdisplay/Sources.pp
+++ b/panda/src/glxdisplay/Sources.pp
@@ -2,7 +2,7 @@
 
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
-#define USE_GL yes
+#define USE_PACKAGES gl glx
 
 #begin lib_target
   #define TARGET glxdisplay
diff --git a/panda/src/ipc/Sources.pp b/panda/src/ipc/Sources.pp
index bd404c7c1b..ac791d9194 100644
--- a/panda/src/ipc/Sources.pp
+++ b/panda/src/ipc/Sources.pp
@@ -1,8 +1,7 @@
 #define LOCAL_LIBS express pandabase
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
-#define USE_NSPR yes
-#define USE_IPC yes
+#define USE_PACKAGES nspr ipc
 #define BUILD_DIRECTORY $[HAVE_IPC]
 
 #begin lib_target
diff --git a/panda/src/mathutil/Sources.pp b/panda/src/mathutil/Sources.pp
index 1efdb18475..82fb5be87d 100644
--- a/panda/src/mathutil/Sources.pp
+++ b/panda/src/mathutil/Sources.pp
@@ -5,7 +5,7 @@
   #define TARGET mathutil
   #define LOCAL_LIBS \
     linmath putil event express
-  #define USE_FFTW yes
+  #define USE_PACKAGES fftw
   #define UNIX_SYS_LIBS m
 
   #define COMBINED_SOURCES $[TARGET]_composite1.cxx $[TARGET]_composite2.cxx 
diff --git a/panda/src/net/Sources.pp b/panda/src/net/Sources.pp
index 9ac79fb91d..353a233499 100644
--- a/panda/src/net/Sources.pp
+++ b/panda/src/net/Sources.pp
@@ -1,8 +1,7 @@
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
 #define BUILD_DIRECTORY $[and $[HAVE_NET],$[HAVE_NSPR]]
-#define USE_NET yes
-#define USE_NSPR yes
+#define USE_PACKAGES net nspr
 
 #begin lib_target
   #define TARGET net
diff --git a/panda/src/parametrics/Sources.pp b/panda/src/parametrics/Sources.pp
index e45d216aa1..4ac7725ea2 100644
--- a/panda/src/parametrics/Sources.pp
+++ b/panda/src/parametrics/Sources.pp
@@ -1,7 +1,7 @@
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
 
-#define USE_NURBSPP yes
+#define USE_PACKAGES nurbspp
 
 #begin lib_target
   #define TARGET parametrics
diff --git a/panda/src/pnmimagetypes/Sources.pp b/panda/src/pnmimagetypes/Sources.pp
index 69e852dec0..c12dd29899 100644
--- a/panda/src/pnmimagetypes/Sources.pp
+++ b/panda/src/pnmimagetypes/Sources.pp
@@ -1,9 +1,6 @@
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
-
-#define USE_TIFF yes
-#define USE_JPEG yes
-#define USE_JPEG2000 yes
+#define USE_PACKAGES tiff jpeg jpeg2000
 
 #begin lib_target
   #define TARGET pnmimagetypes
diff --git a/panda/src/text/Sources.pp b/panda/src/text/Sources.pp
index 92afe46f0c..2c7c080ea0 100644
--- a/panda/src/text/Sources.pp
+++ b/panda/src/text/Sources.pp
@@ -2,7 +2,7 @@
                    dtoolutil:c dtoolbase:c dtool:m
 
 #begin lib_target
-  #define USE_FREETYPE yes
+  #define USE_PACKAGES freetype
 
   #define TARGET text
   #define LOCAL_LIBS \
diff --git a/panda/src/vrpn/Sources.pp b/panda/src/vrpn/Sources.pp
index c7b3feec37..9279d46b71 100644
--- a/panda/src/vrpn/Sources.pp
+++ b/panda/src/vrpn/Sources.pp
@@ -7,7 +7,7 @@
   #define TARGET pvrpn
   #define LOCAL_LIBS \
     device dgraph
-  #define USE_VRPN yes
+  #define USE_PACKAGES vrpn
 
   #define SOURCES \
     config_vrpn.cxx config_vrpn.h vrpnClient.I vrpnClient.cxx \
diff --git a/panda/src/wcrdisplay/Sources.pp b/panda/src/wcrdisplay/Sources.pp
index 733c4044d5..78625d0ee6 100644
--- a/panda/src/wcrdisplay/Sources.pp
+++ b/panda/src/wcrdisplay/Sources.pp
@@ -3,7 +3,7 @@
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
 #define WIN_SYS_LIBS Imm32.lib
-#define USE_CHROMIUM yes
+#define USE_PACKAGES chromium
 
 #begin lib_target
   #define TARGET wcrdisplay
diff --git a/panda/src/wdxdisplay/Sources.pp b/panda/src/wdxdisplay/Sources.pp
index 099c5f2f36..d63c765f52 100644
--- a/panda/src/wdxdisplay/Sources.pp
+++ b/panda/src/wdxdisplay/Sources.pp
@@ -3,7 +3,7 @@
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
 #define WIN_SYS_LIBS Imm32.lib
-#define USE_DX yes
+#define USE_PACKAGES dx
 
 #begin lib_target
   #define TARGET wdxdisplay
diff --git a/panda/src/wdxdisplay8/Sources.pp b/panda/src/wdxdisplay8/Sources.pp
index b74035a8cb..e83fcd04e1 100644
--- a/panda/src/wdxdisplay8/Sources.pp
+++ b/panda/src/wdxdisplay8/Sources.pp
@@ -3,7 +3,7 @@
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
 #define WIN_SYS_LIBS Imm32.lib
-#define USE_DX yes
+#define USE_PACKAGES dx
 
 #begin lib_target
   #define TARGET wdxdisplay8
diff --git a/panda/src/wgldisplay/Sources.pp b/panda/src/wgldisplay/Sources.pp
index fb8787bd9d..fa6a36d76c 100644
--- a/panda/src/wgldisplay/Sources.pp
+++ b/panda/src/wgldisplay/Sources.pp
@@ -1,6 +1,6 @@
 #define BUILD_DIRECTORY $[HAVE_WGL]
 
-#define USE_GL yes
+#define USE_PACKAGES gl
 
 #define OTHER_LIBS interrogatedb:c dconfig:c dtoolconfig:m \
                    dtoolutil:c dtoolbase:c dtool:m
diff --git a/pandatool/src/gtk-stats/Sources.pp b/pandatool/src/gtk-stats/Sources.pp
index 4fa1ca1714..d861acdea3 100644
--- a/pandatool/src/gtk-stats/Sources.pp
+++ b/pandatool/src/gtk-stats/Sources.pp
@@ -1,6 +1,5 @@
 #define BUILD_DIRECTORY $[and $[HAVE_GTKMM],$[HAVE_NET]]
-#define USE_GTKMM yes
-#define USE_NET yes
+#define USE_PACKAGES net gtkmm
 
 #begin bin_target
   #define TARGET gtk-stats
diff --git a/pandatool/src/gtkbase/Sources.pp b/pandatool/src/gtkbase/Sources.pp
index 82939227e0..65d71cd823 100644
--- a/pandatool/src/gtkbase/Sources.pp
+++ b/pandatool/src/gtkbase/Sources.pp
@@ -1,5 +1,5 @@
 #define BUILD_DIRECTORY $[HAVE_GTKMM]
-#define USE_GTKMM yes
+#define USE_PACKAGES gtkmm
 
 #begin ss_lib_target
   #define TARGET gtkbase
diff --git a/pandatool/src/maya/Sources.pp b/pandatool/src/maya/Sources.pp
index 280a937738..1c8c45a67f 100644
--- a/pandatool/src/maya/Sources.pp
+++ b/pandatool/src/maya/Sources.pp
@@ -1,7 +1,7 @@
 #define BUILD_DIRECTORY $[HAVE_MAYA]
 
 #begin ss_lib_target
-  #define USE_MAYA yes
+  #define USE_PACKAGES maya
   #define TARGET maya
   #define LOCAL_LIBS \
     converter pandatoolbase
diff --git a/pandatool/src/mayaegg/Sources.pp b/pandatool/src/mayaegg/Sources.pp
index c266d7972e..37c3e3c5b7 100644
--- a/pandatool/src/mayaegg/Sources.pp
+++ b/pandatool/src/mayaegg/Sources.pp
@@ -1,7 +1,7 @@
 #define BUILD_DIRECTORY $[HAVE_MAYA]
 
 #begin ss_lib_target
-  #define USE_MAYA yes
+  #define USE_PACKAGES maya
   #define TARGET mayaegg
   #define LOCAL_LIBS \
     maya converter pandatoolbase
diff --git a/pandatool/src/mayaprogs/Sources.pp b/pandatool/src/mayaprogs/Sources.pp
index a8577e578a..76da027b39 100644
--- a/pandatool/src/mayaprogs/Sources.pp
+++ b/pandatool/src/mayaprogs/Sources.pp
@@ -22,7 +22,7 @@
 #endif   // $[UNIX_PLATFORM]
 
 #begin bin_target
-  #define USE_MAYA yes
+  #define USE_PACKAGES maya
   #define TARGET $[binary_name]
   #define LOCAL_LIBS \
     mayaegg maya eggbase progbase
@@ -42,7 +42,7 @@
 
 
 #begin bin_target
-  #define USE_MAYA yes
+  #define USE_PACKAGES_maya
   #define TARGET mayacopy
   #define LOCAL_LIBS cvscopy maya progbase
 
diff --git a/pandatool/src/ptloader/Sources.pp b/pandatool/src/ptloader/Sources.pp
index 8ba0304638..8828358972 100644
--- a/pandatool/src/ptloader/Sources.pp
+++ b/pandatool/src/ptloader/Sources.pp
@@ -11,14 +11,14 @@
   #define UNIX_SYS_LIBS \
     m
 
-  #if $[HAVE_DX]
-    // To link in xfile, we need to also link in the DX libraries.
-    #define WIN_SYS_LIBS d3dxof.lib
-    #define USE_DX yes
-  #endif
-
   // If we've got Maya, link in the Maya libraries.
-  #define USE_MAYA yes
+  // To link in xfile, we need to also link in the DX libraries.
+  #define USE_PACKAGES maya dx
+
+  #if $[HAVE_DX]
+    // This should have come in through USE_PACKAGES dx.  Fix this.
+    #define WIN_SYS_LIBS d3dxof.lib
+  #endif
 
   #define SOURCES \
     config_ptloader.cxx config_ptloader.h \
diff --git a/pandatool/src/xfile/Sources.pp b/pandatool/src/xfile/Sources.pp
index 2eec678b88..d18628749e 100644
--- a/pandatool/src/xfile/Sources.pp
+++ b/pandatool/src/xfile/Sources.pp
@@ -2,7 +2,7 @@
 // This package is temporarily disabled.
 #define BUILD_DIRECTORY
 //#define BUILD_DIRECTORY $[HAVE_DX]
-#define USE_DX yes
+#define USE_PACKAGES dx
 
 #begin ss_lib_target
   #define TARGET xfile
diff --git a/pandatool/src/xfileprogs/Sources.pp b/pandatool/src/xfileprogs/Sources.pp
index 2561601303..12c4daf6f4 100644
--- a/pandatool/src/xfileprogs/Sources.pp
+++ b/pandatool/src/xfileprogs/Sources.pp
@@ -2,7 +2,7 @@
 // This package is temporarily disabled.
 #define BUILD_DIRECTORY
 //#define BUILD_DIRECTORY $[HAVE_DX]
-#define USE_DX yes
+#define USE_PACKAGES dx
 
 #begin bin_target
   #define TARGET egg2x