diff --git a/shunit2 b/shunit2
index fd83d51..94e157c 100755
--- a/shunit2
+++ b/shunit2
@@ -630,9 +630,16 @@ failNotEquals() {
   shunit_actual_=$2
 
   shunit_message_=${shunit_message_%% }
-  _shunit_assertFail "${shunit_message_:+${shunit_message_} }expected:<${shunit_expected_}> but was:<${shunit_actual_}>"
+  if command [ "$(echo "${shunit_expected_}" | wc -l)" -gt 10 ] \
+    || command [ "$(echo "${shunit_actual_}" | wc -l)" -gt 10 ];
+    then
+      shunit_diff_=$(diff <(echo "${shunit_expected_}") <(echo "${shunit_actual_}"))
+      _shunit_assertFail "${shunit_message_:+${shunit_message_} }diff:<${shunit_diff_}>"
+  else
+      _shunit_assertFail "${shunit_message_:+${shunit_message_} }expected:<${shunit_expected_}> but was:<${shunit_actual_}>"
+  fi
 
-  unset shunit_message_ shunit_expected_ shunit_actual_
+  unset shunit_message_ shunit_expected_ shunit_actual_ shunit_diff_
   return ${SHUNIT_FALSE}
 }
 # shellcheck disable=SC2016,SC2034