diff -up Macaulay2-1.5/Macaulay2/e/x-factor.cpp.factory_315 Macaulay2-1.5/Macaulay2/e/x-factor.cpp
--- Macaulay2-1.5/Macaulay2/e/x-factor.cpp.factory_315	2012-08-07 08:36:50.484611363 -0500
+++ Macaulay2-1.5/Macaulay2/e/x-factor.cpp	2012-08-07 09:23:51.683341530 -0500
@@ -133,7 +133,7 @@ static __mpz_struct toInteger(CanonicalF
 //     mpz_init(x);
 //     mpz_set(x,y);
 //     return *x;
-     static const unsigned int base = 1 << 16;
+     static const int base = 1 << 16;
      intarray v;
      int sign;
      {