6 files changed, 19 insertions, 2 deletions
diff --git a/testsuite/tests/patsyn/should_compile/T9793.hs b/testsuite/tests/patsyn/should_compile/T9793.hs
new file mode 100644
index 0000000000..230c8618a4
--- /dev/null
+++ b/testsuite/tests/patsyn/should_compile/T9793.hs
@@ -0,0 +1,5 @@
+{-# LANGUAGE PatternSynonyms #-}
+module T9793 where
+
+pattern P :: [a] -> [a]
+pattern P x <- x@(_:_)
diff --git a/testsuite/tests/patsyn/should_compile/all.T b/testsuite/tests/patsyn/should_compile/all.T
index 7ab5ac7e7c..3793c0d322 100644
--- a/testsuite/tests/patsyn/should_compile/all.T
+++ b/testsuite/tests/patsyn/should_compile/all.T
@@ -44,3 +44,4 @@ test('export-record-selector', normal, compile, [''])
 test('T10897', expect_broken(10897), multi_compile, ['T10897', [
                                        ('T10897a.hs','-c')
                                       ,('T10897b.hs', '-c')], ''])
+test('T9793', normal, compile, [''])
diff --git a/testsuite/tests/patsyn/should_fail/T9793-fail.hs b/testsuite/tests/patsyn/should_fail/T9793-fail.hs
new file mode 100644
index 0000000000..2787a8d6ca
--- /dev/null
+++ b/testsuite/tests/patsyn/should_fail/T9793-fail.hs
@@ -0,0 +1,6 @@
+{-# LANGUAGE PatternSynonyms #-}
+
+module Foo where
+
+pattern P :: [a] -> [a]
+pattern P x <- x@(y:_)
diff --git a/testsuite/tests/patsyn/should_fail/T9793-fail.stderr b/testsuite/tests/patsyn/should_fail/T9793-fail.stderr
new file mode 100644
index 0000000000..62713dcd4c
--- /dev/null
+++ b/testsuite/tests/patsyn/should_fail/T9793-fail.stderr
@@ -0,0 +1,4 @@
+
+T9793-fail.hs:6:16: error:
+    Pattern synonym definition cannot contain as-patterns (@) which contain free variables:
+      x@(y : _)
diff --git a/testsuite/tests/patsyn/should_fail/all.T b/testsuite/tests/patsyn/should_fail/all.T
index 6ef64ae5ed..6163da1aab 100644
--- a/testsuite/tests/patsyn/should_fail/all.T
+++ b/testsuite/tests/patsyn/should_fail/all.T
@@ -27,3 +27,4 @@ test('export-type-synonym', normal, compile_fail, [''])
 test('export-ps-rec-sel', normal, compile_fail, [''])
 test('T11053', normal, compile, ['-fwarn-missing-pat-syn-sigs'])
 test('T10426', normal, compile_fail, [''])
+test('T9793-fail', normal, compile_fail, [''])
diff --git a/testsuite/tests/patsyn/should_fail/as-pattern.stderr b/testsuite/tests/patsyn/should_fail/as-pattern.stderr
index 62db28f023..caabd47090 100644
--- a/testsuite/tests/patsyn/should_fail/as-pattern.stderr
+++ b/testsuite/tests/patsyn/should_fail/as-pattern.stderr
@@ -1,4 +1,4 @@
 
-as-pattern.hs:4:18:
-    Pattern synonym definition cannot contain as-patterns (@):
+as-pattern.hs:4:18: error:
+    Pattern synonym definition cannot contain as-patterns (@) which contain free variables:
       x@(Just y)