diff --git a/wptrunner/browsers/servo.py b/wptrunner/browsers/servo.py
index cbc21e607c7895..11499b66b9f42c 100644
--- a/wptrunner/browsers/servo.py
+++ b/wptrunner/browsers/servo.py
@@ -26,8 +26,7 @@ def check_args(**kwargs):
 
 def browser_kwargs(**kwargs):
     return {"binary": kwargs["binary"],
-            "debug_info": kwargs["debug_info"],
-            "interactive": kwargs["interactive"]}
+            "debug_info": kwargs["debug_info"]}
 
 
 def executor_kwargs(test_type, server_config, cache_manager, **kwargs):
@@ -44,13 +43,11 @@ def env_options():
 
 
 class ServoBrowser(NullBrowser):
-    def __init__(self, logger, binary, debug_info=None, interactive=False):
+    def __init__(self, logger, binary, debug_info=None):
         NullBrowser.__init__(self, logger)
         self.binary = binary
         self.debug_info = debug_info
-        self.interactive = interactive
 
     def executor_browser(self):
         return ExecutorBrowser, {"binary": self.binary,
-                                 "debug_info": self.debug_info,
-                                 "interactive": self.interactive}
+                                 "debug_info": self.debug_info}
diff --git a/wptrunner/executors/executorservo.py b/wptrunner/executors/executorservo.py
index e7b2cd415bc505..ef2bffdb2b32a1 100644
--- a/wptrunner/executors/executorservo.py
+++ b/wptrunner/executors/executorservo.py
@@ -21,7 +21,7 @@
                    testharness_result_converter,
                    reftest_result_converter)
 from .process import ProcessTestExecutor
-from ..executors.base import browser_command
+from ..browsers.base import browser_command
 
 hosts_text = """127.0.0.1 web-platform.test
 127.0.0.1 www.web-platform.test
@@ -75,29 +75,35 @@ def do_test(self, test):
         env = os.environ.copy()
         env["HOST_FILE"] = self.hosts_path
 
-        self.proc = ProcessHandler(self.command,
-                                   processOutputLine=[self.on_output],
-                                   onFinish=self.on_finish,
-                                   env=env)
 
-        try:
+
+        if not self.interactive:
+            self.proc = ProcessHandler(self.command,
+                                       processOutputLine=[self.on_output],
+                                       onFinish=self.on_finish,
+                                       env=env,
+                                       storeOutput=False)
             self.proc.run()
+        else:
+            self.proc = subprocess.Popen(self.command, env=env)
 
+        try:
             timeout = test.timeout * self.timeout_multiplier
 
             # Now wait to get the output we expect, or until we reach the timeout
-            if self.debug_info is None and not self.pause_after_test:
+            if not self.interactive and not self.pause_after_test:
                 wait_timeout = timeout + 5
+                self.result_flag.wait(wait_timeout)
             else:
                 wait_timeout = None
-            self.result_flag.wait(wait_timeout)
+                self.proc.wait()
 
             proc_is_running = True
             if self.result_flag.is_set() and self.result_data is not None:
                 self.result_data["test"] = test.url
                 result = self.convert_result(test, self.result_data)
             else:
-                if self.proc.proc.poll() is not None:
+                if self.proc.poll() is not None:
                     result = (test.result_cls("CRASH", None), [])
                     proc_is_running = False
                 else:
diff --git a/wptrunner/executors/process.py b/wptrunner/executors/process.py
index bff8b5bfb53620..45f33ab2c75cb4 100644
--- a/wptrunner/executors/process.py
+++ b/wptrunner/executors/process.py
@@ -9,7 +9,8 @@ class ProcessTestExecutor(TestExecutor):
     def __init__(self, *args, **kwargs):
         TestExecutor.__init__(self, *args, **kwargs)
         self.binary = self.browser.binary
-        self.interactive = self.browser.interactive
+        self.interactive = (False if self.debug_info is None
+                            else self.debug_info.interactive)
 
     def setup(self, runner):
         self.runner = runner
diff --git a/wptrunner/wptcommandline.py b/wptrunner/wptcommandline.py
index 18a5367434d6c8..bf00901ab37124 100644
--- a/wptrunner/wptcommandline.py
+++ b/wptrunner/wptcommandline.py
@@ -276,7 +276,8 @@ def check_args(kwargs):
         debug_info = mozdebug.get_debugger_info(kwargs["debugger"],
                                                 kwargs["debugger_args"])
         if debug_info.interactive:
-            require_arg(kwargs, "processes", lambda x: x == 1)
+            if kwargs["processes"] != 1:
+                kwargs["processes"] = 1
             kwargs["no_capture_stdio"] = True
         kwargs["debug_info"] = debug_info
     else: