Index: driver/cfa.cc
===================================================================
--- driver/cfa.cc	(revision 92a97685f5aabd9745b94f924132f4ef5f9d6868)
+++ driver/cfa.cc	(revision c680a4ba5e93338ec036f1c5135c217e61c20ac1)
@@ -385,9 +385,14 @@
 	} // if
 
+	string preludedir;
 	switch(path) {
-	case Installed   : Putenv( argv, "--prelude-dir=" + libdir ); break;
-	case BuildTree   : Putenv( argv, "--prelude-dir=" + libdir + "/prelude" ); break;
-	case Distributed : Putenv( argv, "--prelude-dir=" + dir(argv[0]) ); break;
+	case Installed   : preludedir = libdir; break;
+	case BuildTree   : preludedir = libdir + "/prelude"; break;
+	case Distributed : preludedir = dir(argv[0]); break;
 	}
+
+	Putenv( argv, "--prelude-dir=" + preludedir );
+	args[nargs++] = "-include";
+	args[nargs++] = (*new string(preludedir + "/defines.hfa")).c_str();
 
 	for ( int i = 0; i < nlibs; i += 1 ) {				// copy non-user libraries after all user libraries