diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 14e1fb323c26..0e94fe136a4c 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2015-01-13  Jason Merrill  <jason@redhat.com>
+
+	PR c++/64520
+	* pt.c (unify): Don't try to deduce to std::initializer_list<T...>.
+
 2015-01-12  Jason Merrill  <jason@redhat.com>
 
 	PR c++/64547
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index d8652fb3d214..3ac93db948a3 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -17854,7 +17854,13 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict,
       if (TREE_CODE (parm) == ARRAY_TYPE)
 	elttype = TREE_TYPE (parm);
       else
-	elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
+	{
+	  elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
+	  /* Deduction is defined in terms of a single type, so just punt
+	     on the (bizarre) std::initializer_list<T...>.  */
+	  if (PACK_EXPANSION_P (elttype))
+	    return unify_success (explain_p);
+	}
 
       FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
 	{
diff --git a/gcc/testsuite/g++.dg/cpp0x/initlist91.C b/gcc/testsuite/g++.dg/cpp0x/initlist91.C
new file mode 100644
index 000000000000..1387557ab2d2
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/initlist91.C
@@ -0,0 +1,8 @@
+// PR c++/64520
+// { dg-do compile { target c++11 } }
+
+#include <initializer_list>
+struct A {
+  template <typename... B> A(std::initializer_list<B...>);
+};
+A a { 0 };			// { dg-error "" }