5 files changed, 16 insertions, 1 deletions
diff --git a/compiler/iface/IfaceSyn.hs b/compiler/iface/IfaceSyn.hs
index 562d816938..c3f8933576 100644
--- a/compiler/iface/IfaceSyn.hs
+++ b/compiler/iface/IfaceSyn.hs
@@ -1114,7 +1114,7 @@ pprIfaceConDecl ss gadt_style tycon tc_binders parent
     --    [VarBndrs, TyCoVarBinders, TyConBinders, and visibility] in TyCoRep.)
     ppr_tc_app gadt_subst =
       pprPrefixIfDeclBndr how_much (occName tycon)
-      <+> pprIfaceAppArgs
+      <+> pprParendIfaceAppArgs
             (substIfaceAppArgs gadt_subst (mk_tc_app_args tc_binders))
 
     mk_tc_app_args :: [IfaceTyConBinder] -> IfaceAppArgs
diff --git a/testsuite/tests/ghci/scripts/T17384.hs b/testsuite/tests/ghci/scripts/T17384.hs
new file mode 100644
index 0000000000..ce9216b59f
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T17384.hs
@@ -0,0 +1,8 @@
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE KindSignatures #-}
+module T17384 where
+
+import Data.Kind
+
+data T :: Type -> Type where
+  MkT :: T (Maybe Bool)
diff --git a/testsuite/tests/ghci/scripts/T17384.script b/testsuite/tests/ghci/scripts/T17384.script
new file mode 100644
index 0000000000..7274d86aaf
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T17384.script
@@ -0,0 +1,2 @@
+:load T17384
+:info T
diff --git a/testsuite/tests/ghci/scripts/T17384.stdout b/testsuite/tests/ghci/scripts/T17384.stdout
new file mode 100644
index 0000000000..189cc4b6cc
--- /dev/null
+++ b/testsuite/tests/ghci/scripts/T17384.stdout
@@ -0,0 +1,4 @@
+type role T nominal
+data T a where
+  MkT :: T (Maybe Bool)
+  	-- Defined at T17384.hs:7:1
diff --git a/testsuite/tests/ghci/scripts/all.T b/testsuite/tests/ghci/scripts/all.T
index 708bd9f8f9..f5ae669a67 100755
--- a/testsuite/tests/ghci/scripts/all.T
+++ b/testsuite/tests/ghci/scripts/all.T
@@ -299,3 +299,4 @@ test('T16509', normal, ghci_script, ['T16509.script'])
 test('T16527', normal, ghci_script, ['T16527.script'])
 test('T16563', extra_hc_opts("-clear-package-db -global-package-db"), ghci_script, ['T16563.script'])
 test('T16767', normal, ghci_script, ['T16767.script'])
+test('T17384', normal, ghci_script, ['T17384.script'])