diff -u ppl-0.12.1_unpatched/src/mp_std_bits.cc ppl-0.12.1/src/mp_std_bits.cc
--- ppl-0.12.1_unpatched/src/mp_std_bits.cc	2012-04-16 14:12:30.000000000 +0200
+++ ppl-0.12.1/src/mp_std_bits.cc	2012-12-26 12:41:32.843371211 +0100
@@ -45,7 +45,11 @@
 const bool std::numeric_limits<mpz_class>::is_bounded;
 const bool std::numeric_limits<mpz_class>::is_modulo;
 const bool std::numeric_limits<mpz_class>::traps;
+#if __GNU_MP_RELEASE < 50100
 const bool std::numeric_limits<mpz_class>::tininess_before;
+#else
+const bool std::numeric_limits<mpz_class>::tinyness_before;
+#endif
 const std::float_round_style std::numeric_limits<mpz_class>::round_style;
 
 const bool std::numeric_limits<mpq_class>::is_specialized;
@@ -68,5 +72,9 @@
 const bool std::numeric_limits<mpq_class>::is_bounded;
 const bool std::numeric_limits<mpq_class>::is_modulo;
 const bool std::numeric_limits<mpq_class>::traps;
+#if __GNU_MP_RELEASE < 50100
 const bool std::numeric_limits<mpq_class>::tininess_before;
+#else
+const bool std::numeric_limits<mpq_class>::tinyness_before;
+#endif
 const std::float_round_style std::numeric_limits<mpq_class>::round_style;
diff -u ppl-0.12.1_unpatched/src/mp_std_bits.defs.hh ppl-0.12.1/src/mp_std_bits.defs.hh
--- ppl-0.12.1_unpatched/src/mp_std_bits.defs.hh	2012-04-16 14:12:30.000000000 +0200
+++ ppl-0.12.1/src/mp_std_bits.defs.hh	2012-12-26 12:31:32.715248648 +0100
@@ -38,6 +38,7 @@
 #endif // defined(PPL_DOXYGEN_INCLUDE_IMPLEMENTATION_DETAILS)
 void swap(mpq_class& x, mpq_class& y);
 
+#if __GNU_MP_RELEASE < 50100
 namespace std {
 
 #ifdef PPL_DOXYGEN_INCLUDE_IMPLEMENTATION_DETAILS
@@ -164,6 +165,7 @@
 
 } // namespace std
 
+#endif // __GNU_MP_RELEASE < 50100
 #include "mp_std_bits.inlines.hh"
 
 #endif // !defined(PPL_mp_std_bits_defs_hh)