1 files changed, 28 insertions, 11 deletions
diff --git a/testsuite/tests/gadt/T3169.stderr b/testsuite/tests/gadt/T3169.stderr
index 878324caeb..c1ee5b5e2f 100644
--- a/testsuite/tests/gadt/T3169.stderr
+++ b/testsuite/tests/gadt/T3169.stderr
@@ -1,11 +1,28 @@
-
-T3169.hs:13:13:
-    Couldn't match type `elt' with `Map b elt'
-      `elt' is a rigid type variable bound by
-            the type signature for
-              lookup :: (a, b) -> Map (a, b) elt -> Maybe elt
-            at T3169.hs:12:3
-    Expected type: Maybe (Map b elt)
-      Actual type: Maybe elt
-    In the return type of a call of `lookup'
-    In the expression: lookup a m :: Maybe (Map b elt)
+
+T3169.hs:13:13:
+    Could not deduce (elt ~ Map b elt)
+    from the context (Key a, Key b)
+      bound by the instance declaration at T3169.hs:10:10-36
+      `elt' is a rigid type variable bound by
+            the type signature for
+              lookup :: (a, b) -> Map (a, b) elt -> Maybe elt
+            at T3169.hs:12:3
+    Expected type: Maybe (Map b elt)
+      Actual type: Maybe elt
+    In the return type of a call of `lookup'
+    In the expression: lookup a m :: Maybe (Map b elt)
+    In the expression:
+      case lookup a m :: Maybe (Map b elt) of {
+        Just (m2 :: Map b elt) -> lookup b m2 :: Maybe elt }
+
+T3169.hs:13:22:
+    Could not deduce (Map a ~ MP a b)
+    from the context (Key a, Key b)
+      bound by the instance declaration at T3169.hs:10:10-36
+    Expected type: Map a elt
+      Actual type: Map (a, b) elt
+    In the second argument of `lookup', namely `m'
+    In the expression: lookup a m :: Maybe (Map b elt)
+    In the expression:
+      case lookup a m :: Maybe (Map b elt) of {
+        Just (m2 :: Map b elt) -> lookup b m2 :: Maybe elt }