diff --git a/testsuite/tests/typecheck/should_compile/T10770a.hs b/testsuite/tests/typecheck/should_compile/T10770a.hs
new file mode 100644
index 0000000000000000000000000000000000000000..611c86e35d742c8c1a223f20e904263a60a7ea2d
--- /dev/null
+++ b/testsuite/tests/typecheck/should_compile/T10770a.hs
@@ -0,0 +1,8 @@
+module T10770a where
+
+import Data.Typeable
+
+main = print $ foo $ Just ()
+
+foo :: Typeable (t a) => t a -> String
+foo x = let k = show $ typeOf x in k
diff --git a/testsuite/tests/typecheck/should_compile/T10770b.hs b/testsuite/tests/typecheck/should_compile/T10770b.hs
new file mode 100644
index 0000000000000000000000000000000000000000..62ae61cb6b3b8f5a83197643603b7f32d59b2421
--- /dev/null
+++ b/testsuite/tests/typecheck/should_compile/T10770b.hs
@@ -0,0 +1,9 @@
+{-# LANGUAGE FlexibleContexts #-}
+{-# OPTIONS_GHC -fwarn-redundant-constraints #-}
+module T10770b where
+
+f :: (Show a, Show (Maybe a)) => Maybe a -> String
+f x = let k = show x in k
+
+g :: (Show a, Show (Maybe a)) => Maybe a -> String
+g x = show x
diff --git a/testsuite/tests/typecheck/should_compile/all.T b/testsuite/tests/typecheck/should_compile/all.T
index 6f34db479965404bbae6271052462425209216a0..da71c1d742c69c1f342e990c5174c890ed72ba89 100644
--- a/testsuite/tests/typecheck/should_compile/all.T
+++ b/testsuite/tests/typecheck/should_compile/all.T
@@ -475,3 +475,5 @@ test('T10642', normal, compile, [''])
 test('T10744', normal, compile, [''])
 test('update-existential', normal, compile, [''])
 test('T10347', expect_broken(10347), compile, [''])
+test('T10770a', expect_broken(10770), compile, [''])
+test('T10770b', expect_broken(10770), compile, [''])