diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 1a071e95004dcf818fe7372e5771cdc06144cf29..f636bac54134423e2a2713a7e4d3bf27ef051acc 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -10355,6 +10355,12 @@ lookup_and_finish_template_variable (tree templ, tree targs,
   if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (templ)) == 1
       && !any_dependent_template_arguments_p (targs))
     {
+      /* We may be called while doing a partial substitution, but the
+	 type of the variable template may be auto, in which case we
+	 will call do_auto_deduction in mark_used (which clears tf_partial)
+	 and the auto must be properly reduced at that time for the
+	 deduction to work.  */
+      complain &= ~tf_partial;
       var = finish_template_variable (var, complain);
       mark_used (var);
     }
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ70.C b/gcc/testsuite/g++.dg/cpp1y/var-templ70.C
new file mode 100644
index 0000000000000000000000000000000000000000..1d35c38c7cc4efeff4778ecbadc12f032513e5e9
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ70.C
@@ -0,0 +1,25 @@
+// PR c++/108550
+// { dg-do compile { target c++14 } }
+
+template<class T>
+struct is_pointer
+{
+  static constexpr bool value = false;
+};
+
+template<class T, T T1>
+struct integral_constant
+{
+  static constexpr T value = T1;
+};
+
+
+template <class Tp>
+constexpr auto is_pointer_v = is_pointer<Tp>::value;
+
+template <class Tp, int = 0>
+integral_constant<bool, is_pointer_v<int>> Wrap1();
+
+int main() {
+  static_assert(!decltype(Wrap1<int>())::value, "");
+}
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ71.C b/gcc/testsuite/g++.dg/cpp1y/var-templ71.C
new file mode 100644
index 0000000000000000000000000000000000000000..e0cf55230d934992a3511d5786c13ec395ef265d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ71.C
@@ -0,0 +1,26 @@
+// PR c++/108550
+// { dg-do compile { target c++14 } }
+
+template<class T, T T1>
+struct integral_constant
+{
+  static constexpr T value = T1;
+};
+
+template <typename T>
+struct S {
+  template <typename U, typename V>
+  static constexpr void foo(V) { }
+
+  constexpr bool bar () const { foo<int>(10); return false; }
+};
+
+template <class Tp>
+constexpr auto is_pointer_v = S<Tp>{}.bar();
+
+template <class Tp, int = 0>
+integral_constant<bool, is_pointer_v<int>> Wrap1();
+
+int main() {
+  static_assert(!decltype(Wrap1<int>())::value, "");
+}
diff --git a/gcc/testsuite/g++.dg/cpp1y/var-templ72.C b/gcc/testsuite/g++.dg/cpp1y/var-templ72.C
new file mode 100644
index 0000000000000000000000000000000000000000..7426bad4a6ccb14f0a0667cea6cd193ce4a25b9f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1y/var-templ72.C
@@ -0,0 +1,27 @@
+// PR c++/108550
+// { dg-do compile { target c++14 } }
+
+template<class T>
+struct is_pointer
+{
+  static constexpr bool value = false;
+};
+
+template<class T, T T1>
+struct integral_constant
+{
+  static constexpr T value = T1;
+};
+
+template<typename T>
+using PTR_P = is_pointer<T>;
+
+template <class Tp>
+constexpr auto is_pointer_v = PTR_P<Tp>::value;
+
+template <class Tp, int = 0>
+integral_constant<bool, is_pointer_v<Tp>> Wrap1();
+
+int main() {
+  static_assert(!decltype(Wrap1<int>())::value, "");
+}