diff --git a/direct/src/directbase/Sources.pp b/direct/src/directbase/Sources.pp
index dae2615e6a..c463cdaade 100644
--- a/direct/src/directbase/Sources.pp
+++ b/direct/src/directbase/Sources.pp
@@ -9,4 +9,12 @@
   #define INSTALL_HEADERS \
     directbase.h directsymbols.h
 
+  // These libraries and frameworks are used by dtoolutil; we redefine
+  // them here so they get into the panda build system.
+  #if $[ne $[PLATFORM], FreeBSD]
+    #define UNIX_SYS_LIBS dl
+  #endif
+  #define WIN_SYS_LIBS shell32.lib
+  #define OSX_SYS_FRAMEWORKS Foundation $[if $[not $[BUILD_IPHONE]],AppKit]
+
 #end lib_target