diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 7ac074a19b6..65fc6447e74 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,7 @@
+2020-05-17  Iain Sandoe  <iain@sandoe.co.uk>
+
+	* coroutines.cc (morph_fn_to_coro): Initialize the gro variable.
+
 2020-05-16  Iain Sandoe  <iain@sandoe.co.uk>
 
 	* coroutines.cc (finish_co_return_stmt): Implement rules
diff --git a/gcc/cp/coroutines.cc b/gcc/cp/coroutines.cc
index facfafaaa86..4cbc0e09994 100644
--- a/gcc/cp/coroutines.cc
+++ b/gcc/cp/coroutines.cc
@@ -4285,7 +4285,8 @@ morph_fn_to_coro (tree orig, tree *resumer, tree *destroyer)
   tree gro_context_body = push_stmt_list ();
   bool gro_is_void_p = VOID_TYPE_P (TREE_TYPE (get_ro));
 
-  tree gro, gro_bind_vars = NULL_TREE;
+  tree gro = NULL_TREE;
+  tree gro_bind_vars = NULL_TREE;
   /* We have to sequence the call to get_return_object before initial
      suspend.  */
   if (gro_is_void_p)