diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index b1c9e01e7b0b..e884898115cd 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-05  Jason Merrill  <jason@redhat.com>
+
+	PR c++/46304
+	* pt.c (tsubst_copy): Handle COMPLEX_CST.
+
 2010-11-04  Nicola Pero  <nicola.pero@meta-innovation.com>
 
 	Fixed using the Objective-C 2.0 dot-syntax with class names.	
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index ca2baebee430..ed04b2be59ea 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -11658,6 +11658,7 @@ tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
     case INTEGER_CST:
     case REAL_CST:
     case STRING_CST:
+    case COMPLEX_CST:
       {
 	/* Instantiate any typedefs in the type.  */
 	tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a1fb0b11d0c1..90e13ddfb1b9 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-05  Jason Merrill  <jason@redhat.com>
+
+	PR c++/46304
+	* g++.dg/ext/complex6.C: New.
+
 2010-11-04  Bud Davis	<jimmied@smu.edu>
 
 	* gfortran.dg/intrinsic_numeric_arg.f: Add test to check 
diff --git a/gcc/testsuite/g++.dg/ext/complex6.C b/gcc/testsuite/g++.dg/ext/complex6.C
new file mode 100644
index 000000000000..9a7c50a7ae52
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/complex6.C
@@ -0,0 +1,10 @@
+// PR c++/46304
+// { dg-options "" }
+
+template<class T>
+void f()
+{
+  __complex double d =  1.0 + 2.0i;
+}
+
+template void f<int>();