diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 5623bcf97b1..3da96feb02b 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,8 @@
 2011-12-19  Jason Merrill  <jason@redhat.com>
 
+	PR c++/51530
+	* pt.c (unify): Handle NULLPTR_TYPE.
+
 	PR c++/51526
 	* semantics.c (build_data_member_initialization): Handle
 	delegating constructor.
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 66d4c3fb7fe..769b610cc47 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -16614,6 +16614,7 @@ unify (tree tparms, tree targs, tree parm, tree arg, int strict,
     case BOOLEAN_TYPE:
     case ENUMERAL_TYPE:
     case VOID_TYPE:
+    case NULLPTR_TYPE:
       if (TREE_CODE (arg) != TREE_CODE (parm))
 	return unify_type_mismatch (explain_p, parm, arg);
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9efe801c983..7b349c922c5 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-12-19  Jason Merrill  <jason@redhat.com>
+
+	PR c++/51530
+	* g++.dg/cpp0x/nullptr26.C: New.
+
 2011-12-19  Richard Sandiford  <rdsandiford@googlemail.com>
 
 	* gcc.target/mips/mult-1.c: Require -O2.
diff --git a/gcc/testsuite/g++.dg/cpp0x/nullptr26.C b/gcc/testsuite/g++.dg/cpp0x/nullptr26.C
new file mode 100644
index 00000000000..b7421b8d048
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/nullptr26.C
@@ -0,0 +1,13 @@
+// PR c++/51530
+// { dg-options -std=c++0x }
+
+template <class T, class U>
+void f(T, U);
+
+template <class T>
+void f(T, decltype(nullptr));
+
+int main()
+{
+  f(1, nullptr);
+}