diff --git a/apps/log_monitor/src/gatherer.erl b/apps/log_monitor/src/gatherer.erl
index afd91ff..60a8342 100644
--- a/apps/log_monitor/src/gatherer.erl
+++ b/apps/log_monitor/src/gatherer.erl
@@ -242,7 +242,7 @@ start_test() ->
     {ok, _Pid} = start_link("/tmp/test.log", "ERROR").
 
 is_error_test() ->
-    ?assert(not is_error("2017-01-01 MyApp - WARN: abc", "ERROR")),
+    ?assertNot(is_error("2017-01-01 MyApp - WARN: abc", "ERROR")),
     ?assert(is_error("2017-01-01 MyApp - ERROR: abc", "ERROR")).
 
 -endif.