diff --git a/testsuite/tests/rename/should_fail/T5951.hs b/testsuite/tests/rename/should_fail/T5951.hs
new file mode 100644
index 0000000000000000000000000000000000000000..70756795f67f9bce06e4a86b6d43be1cbd26a811
--- /dev/null
+++ b/testsuite/tests/rename/should_fail/T5951.hs
@@ -0,0 +1,11 @@
+module T5951 where
+
+class A a 
+class B b
+class C c
+
+instance
+       A =>
+       B =>
+       C where
+         foo = undefined
diff --git a/testsuite/tests/rename/should_fail/T5951.stderr b/testsuite/tests/rename/should_fail/T5951.stderr
new file mode 100644
index 0000000000000000000000000000000000000000..af0ee9d431e89cd2669a996b48a01bfc6a281b8a
--- /dev/null
+++ b/testsuite/tests/rename/should_fail/T5951.stderr
@@ -0,0 +1,2 @@
+
+T5951.hs:8:8: Malformed instance: A => B => C
diff --git a/testsuite/tests/rename/should_fail/all.T b/testsuite/tests/rename/should_fail/all.T
index c762efcf415223ae7184809f225a898ceaea741f..a512d196d7e6bfa1d90b3c2978cee1e93c21cd17 100644
--- a/testsuite/tests/rename/should_fail/all.T
+++ b/testsuite/tests/rename/should_fail/all.T
@@ -101,3 +101,4 @@ test('T5745',
      multimod_compile_fail, ['T5745', '-v0'])
 test('T5892a', normal, compile_fail, [''])
 test('T5892b', normal, compile_fail, [''])
+test('T5951', normal, compile_fail, [''])