diff --git a/libcxx/test/std/thread/futures/futures.task/futures.task.members/assign_move.pass.cpp b/libcxx/test/std/thread/futures/futures.task/futures.task.members/assign_move.pass.cpp
--- a/libcxx/test/std/thread/futures/futures.task/futures.task.members/assign_move.pass.cpp
+++ b/libcxx/test/std/thread/futures/futures.task/futures.task.members/assign_move.pass.cpp
@@ -39,7 +39,7 @@
         assert(!p0.valid());
         assert(p.valid());
         std::future<double> f = p.get_future();
-        p(3, 'a');
+        p(3, 97);
         assert(f.get() == 105.0);
     }
     {
diff --git a/libcxx/test/std/thread/futures/futures.task/futures.task.members/ctor_func.pass.cpp b/libcxx/test/std/thread/futures/futures.task/futures.task.members/ctor_func.pass.cpp
--- a/libcxx/test/std/thread/futures/futures.task/futures.task.members/ctor_func.pass.cpp
+++ b/libcxx/test/std/thread/futures/futures.task/futures.task.members/ctor_func.pass.cpp
@@ -47,7 +47,7 @@
         std::packaged_task<double(int, char)> p(A(5));
         assert(p.valid());
         std::future<double> f = p.get_future();
-        p(3, 'a');
+        p(3, 97);
         assert(f.get() == 105.0);
         assert(A::n_copies == 0);
         assert(A::n_moves > 0);
@@ -59,7 +59,7 @@
         std::packaged_task<double(int, char)> p(a);
         assert(p.valid());
         std::future<double> f = p.get_future();
-        p(3, 'a');
+        p(3, 97);
         assert(f.get() == 105.0);
         assert(A::n_copies > 0);
         assert(A::n_moves > 0);
diff --git a/libcxx/test/std/thread/futures/futures.task/futures.task.members/ctor_move.pass.cpp b/libcxx/test/std/thread/futures/futures.task/futures.task.members/ctor_move.pass.cpp
--- a/libcxx/test/std/thread/futures/futures.task/futures.task.members/ctor_move.pass.cpp
+++ b/libcxx/test/std/thread/futures/futures.task/futures.task.members/ctor_move.pass.cpp
@@ -38,7 +38,7 @@
         assert(!p0.valid());
         assert(p.valid());
         std::future<double> f = p.get_future();
-        p(3, 'a');
+        p(3, 97);
         assert(f.get() == 105.0);
     }
     {
diff --git a/libcxx/test/std/thread/futures/futures.task/futures.task.members/dtor.pass.cpp b/libcxx/test/std/thread/futures/futures.task/futures.task.members/dtor.pass.cpp
--- a/libcxx/test/std/thread/futures/futures.task/futures.task.members/dtor.pass.cpp
+++ b/libcxx/test/std/thread/futures/futures.task/futures.task.members/dtor.pass.cpp
@@ -35,10 +35,7 @@
 {
 }
 
-void func2(std::packaged_task<double(int, char)> p)
-{
-    p(3, 'a');
-}
+void func2(std::packaged_task<double(int, char)> p) { p(3, 97); }
 
 int main(int, char**)
 {
diff --git a/libcxx/test/std/thread/futures/futures.task/futures.task.members/get_future.pass.cpp b/libcxx/test/std/thread/futures/futures.task/futures.task.members/get_future.pass.cpp
--- a/libcxx/test/std/thread/futures/futures.task/futures.task.members/get_future.pass.cpp
+++ b/libcxx/test/std/thread/futures/futures.task/futures.task.members/get_future.pass.cpp
@@ -35,7 +35,7 @@
     {
         std::packaged_task<double(int, char)> p(A(5));
         std::future<double> f = p.get_future();
-        p(3, 'a');
+        p(3, 97);
         assert(f.get() == 105.0);
     }
 #ifndef TEST_HAS_NO_EXCEPTIONS
diff --git a/libcxx/test/std/thread/futures/futures.task/futures.task.members/make_ready_at_thread_exit.pass.cpp b/libcxx/test/std/thread/futures/futures.task/futures.task.members/make_ready_at_thread_exit.pass.cpp
--- a/libcxx/test/std/thread/futures/futures.task/futures.task.members/make_ready_at_thread_exit.pass.cpp
+++ b/libcxx/test/std/thread/futures/futures.task/futures.task.members/make_ready_at_thread_exit.pass.cpp
@@ -30,31 +30,30 @@
 
     long operator()(long i, long j) const
     {
-        if (j == 'z')
-            TEST_THROW(A(6));
-        return data_ + i + j;
+      if (j == 122)
+        TEST_THROW(A(6));
+      return data_ + i + j;
     }
 };
 
 void func0(std::packaged_task<double(int, char)> p)
 {
     std::this_thread::sleep_for(std::chrono::milliseconds(500));
-    p.make_ready_at_thread_exit(3, 'a');
+    p.make_ready_at_thread_exit(3, 97);
 }
 
 void func1(std::packaged_task<double(int, char)> p)
 {
     std::this_thread::sleep_for(std::chrono::milliseconds(500));
-    p.make_ready_at_thread_exit(3, 'z');
+    p.make_ready_at_thread_exit(3, 122);
 }
 
 void func2(std::packaged_task<double(int, char)> p)
 {
 #ifndef TEST_HAS_NO_EXCEPTIONS
-    p.make_ready_at_thread_exit(3, 'a');
-    try
-    {
-        p.make_ready_at_thread_exit(3, 'c');
+  p.make_ready_at_thread_exit(3, 97);
+  try {
+    p.make_ready_at_thread_exit(3, 99);
     }
     catch (const std::future_error& e)
     {
@@ -70,7 +69,7 @@
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        p.make_ready_at_thread_exit(3, 'a');
+      p.make_ready_at_thread_exit(3, 97);
     }
     catch (const std::future_error& e)
     {
@@ -101,7 +100,7 @@
         }
         catch (const A& e)
         {
-            assert(e(3, 'a') == 106);
+          assert(e(3, 97) == 106.0);
         }
     }
     {
diff --git a/libcxx/test/std/thread/futures/futures.task/futures.task.members/operator.pass.cpp b/libcxx/test/std/thread/futures/futures.task/futures.task.members/operator.pass.cpp
--- a/libcxx/test/std/thread/futures/futures.task/futures.task.members/operator.pass.cpp
+++ b/libcxx/test/std/thread/futures/futures.task/futures.task.members/operator.pass.cpp
@@ -30,31 +30,30 @@
 
     long operator()(long i, long j) const
     {
-        if (j == 'z')
-            TEST_THROW(A(6));
-        return data_ + i + j;
+      if (j == 122)
+        TEST_THROW(A(6));
+      return data_ + i + j;
     }
 };
 
 void func0(std::packaged_task<double(int, char)> p)
 {
     std::this_thread::sleep_for(std::chrono::milliseconds(500));
-    p(3, 'a');
+    p(3, 97);
 }
 
 void func1(std::packaged_task<double(int, char)> p)
 {
     std::this_thread::sleep_for(std::chrono::milliseconds(500));
-    p(3, 'z');
+    p(3, 122);
 }
 
 void func2(std::packaged_task<double(int, char)> p)
 {
 #ifndef TEST_HAS_NO_EXCEPTIONS
-    p(3, 'a');
-    try
-    {
-        p(3, 'c');
+  p(3, 97);
+  try {
+    p(3, 99);
     }
     catch (const std::future_error& e)
     {
@@ -70,7 +69,7 @@
 #ifndef TEST_HAS_NO_EXCEPTIONS
     try
     {
-        p(3, 'a');
+      p(3, 97);
     }
     catch (const std::future_error& e)
     {
@@ -101,7 +100,7 @@
         }
         catch (const A& e)
         {
-            assert(e(3, 'a') == 106);
+          assert(e(3, 97) == 106.0);
         }
     }
     {
diff --git a/libcxx/test/std/thread/futures/futures.task/futures.task.members/reset.pass.cpp b/libcxx/test/std/thread/futures/futures.task/futures.task.members/reset.pass.cpp
--- a/libcxx/test/std/thread/futures/futures.task/futures.task.members/reset.pass.cpp
+++ b/libcxx/test/std/thread/futures/futures.task/futures.task.members/reset.pass.cpp
@@ -38,10 +38,10 @@
     {
         std::packaged_task<double(int, char)> p(A(5));
         std::future<double> f = p.get_future();
-        p(3, 'a');
+        p(3, 97);
         assert(f.get() == 105.0);
         p.reset();
-        p(4, 'a');
+        p(4, 97);
         f = p.get_future();
         assert(f.get() == 106.0);
     }
diff --git a/libcxx/test/std/thread/futures/futures.task/futures.task.members/swap.pass.cpp b/libcxx/test/std/thread/futures/futures.task/futures.task.members/swap.pass.cpp
--- a/libcxx/test/std/thread/futures/futures.task/futures.task.members/swap.pass.cpp
+++ b/libcxx/test/std/thread/futures/futures.task/futures.task.members/swap.pass.cpp
@@ -39,7 +39,7 @@
         assert(!p0.valid());
         assert(p.valid());
         std::future<double> f = p.get_future();
-        p(3, 'a');
+        p(3, 97);
         assert(f.get() == 105.0);
     }
     {
diff --git a/libcxx/test/std/thread/futures/futures.task/futures.task.nonmembers/swap.pass.cpp b/libcxx/test/std/thread/futures/futures.task/futures.task.nonmembers/swap.pass.cpp
--- a/libcxx/test/std/thread/futures/futures.task/futures.task.nonmembers/swap.pass.cpp
+++ b/libcxx/test/std/thread/futures/futures.task/futures.task.nonmembers/swap.pass.cpp
@@ -41,7 +41,7 @@
         assert(!p0.valid());
         assert(p.valid());
         std::future<double> f = p.get_future();
-        p(3, 'a');
+        p(3, 97);
         assert(f.get() == 105.0);
     }
     {