diff --git a/src/Hooks.cpp b/src/Hooks.cpp
index 8947bb74c..08fd5eeac 100644
--- a/src/Hooks.cpp
+++ b/src/Hooks.cpp
@@ -402,6 +402,9 @@ bool Hooks::isJSON (const std::string& input) const
       input[input.length () - 1] != '}')
     return false;
 
+/*
+  I think this is not necessary, and a simple JSON test is all that is needed.
+
   try
   {
     json::value* root = json::parse (input);
@@ -419,6 +422,7 @@ bool Hooks::isJSON (const std::string& input) const
   {
     return false;
   }
+*/
 
   return true;
 }
@@ -481,11 +485,11 @@ void Hooks::assertValidJSON (const std::vector <std::string>& input) const
 }
 
 ////////////////////////////////////////////////////////////////////////////////
-void Hooks::assertNTasks (const std::vector <std::string>& json, int n) const
+void Hooks::assertNTasks (const std::vector <std::string>& input, int n) const
 {
-  if (json.size () != n)
+  if (input.size () != n)
   {
-    context.error (format ("Hook Error: Expected {1} JSON task(s), found {2}", n, (int) json.size ()));
+    context.error (format ("Hook Error: Expected {1} JSON task(s), found {2}", n, (int) input.size ()));
     throw 0;
   }
 }
diff --git a/test/hooks.on-launch.t b/test/hooks.on-launch.t
index 56c0d970a..9a2955286 100755
--- a/test/hooks.on-launch.t
+++ b/test/hooks.on-launch.t
@@ -83,6 +83,20 @@ class TestHooksOnLaunch(TestCase):
         logs = self.t.hooks[hookname].get_logs()
         self.assertEqual(self.t.hooks[hookname].get_logs()["output"]["msgs"][0], "FEEDBACK")
 
+    def test_onlaunch_builtin_misbehave2(self):
+        """on-launch-misbehave2 - Hook emits unexpected JSON."""
+        hookname = 'on-launch-misbehave2'
+        self.t.hooks.add_default(hookname, log=True)
+
+        # Failing hook should prevent processing.
+        code, out, err = self.t.runError(("version",))
+        self.assertIn("Hook Error: Expected 0 JSON task(s), found 1", err)
+        self.t.hooks[hookname].assertTriggered()
+        self.t.hooks[hookname].assertTriggeredCount(1)
+        self.t.hooks[hookname].assertExitcode(0)
+        logs = self.t.hooks[hookname].get_logs()
+        self.assertEqual(self.t.hooks[hookname].get_logs()["output"]["msgs"][0], "FEEDBACK")
+
 if __name__ == "__main__":
     from simpletap import TAPTestRunner
     unittest.main(testRunner=TAPTestRunner())
diff --git a/test/test_hooks/on-launch-misbehave2 b/test/test_hooks/on-launch-misbehave2
new file mode 100644
index 000000000..f981f8d68
--- /dev/null
+++ b/test/test_hooks/on-launch-misbehave2
@@ -0,0 +1,18 @@
+#!/bin/sh
+
+# The on-launch event is triggered once, after initialization, before any
+# processing occurs. This hooks script has no effect on processing.
+
+# Input:
+# - None
+
+# Output:
+# - Optional feedback/error.
+echo '{"description":"extra","status":"pending"}'
+echo 'FEEDBACK'
+
+# Status:
+# - 0:     JSON ignored, non-JSON is feedback.
+# - non-0: JSON ignored, non-JSON is error.
+exit 0
+