diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index e71b4fbe9d8..ba323bf7c20 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,8 @@
+2018-04-06  Jason Merrill  <jason@redhat.com>
+
+	PR c++/85214 - ICE with alias, generic lambda, constexpr if.
+	* pt.c (extract_locals_r): Remember local typedefs.
+
 2018-04-06  David Malcolm  <dmalcolm@redhat.com>
 
 	PR c++/84269
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 450ffaec9be..db3d7e38d85 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -11610,6 +11610,11 @@ extract_locals_r (tree *tp, int */*walk_subtrees*/, void *data_)
   el_data &data = *reinterpret_cast<el_data*>(data_);
   tree *extra = &data.extra;
   tsubst_flags_t complain = data.complain;
+
+  if (TYPE_P (*tp) && typedef_variant_p (*tp))
+    /* Remember local typedefs (85214).  */
+    tp = &TYPE_NAME (*tp);
+
   if (TREE_CODE (*tp) == DECL_EXPR)
     data.internal.add (DECL_EXPR_DECL (*tp));
   else if (tree spec = retrieve_local_specialization (*tp))
diff --git a/gcc/testsuite/g++.dg/cpp1z/constexpr-if20.C b/gcc/testsuite/g++.dg/cpp1z/constexpr-if20.C
new file mode 100644
index 00000000000..24343adb748
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/constexpr-if20.C
@@ -0,0 +1,17 @@
+// PR c++/85214
+// { dg-additional-options -std=c++17 }
+
+struct g {
+  constexpr operator int() { return true; }
+};
+template <typename T, typename U> constexpr bool m = true;
+template <long L> struct C { typedef double q; };
+void ao() {
+  [](auto i) {
+      using ar = typename C<i>::q;
+      [](auto j) {
+	using as = typename C<j>::q;
+	if constexpr (m<ar, as>) {}
+      }(g());
+  }(g());
+}