diff --git a/CHANGELOG.md b/CHANGELOG.md
index b08439a695..7fbc913ce2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
+## [UNRELEASED]
+### Fixed
+- [#1384](https://github.com/plotly/dash/pull/1384) Fixed a bug introduced by [#1180](https://github.com/plotly/dash/pull/1180) breaking use of `prevent_initial_call` as a positional arg in callback definitions
+
 ## [1.15.0] - 2020-08-25
 ### Added
 - [#1355](https://github.com/plotly/dash/pull/1355) Removed redundant log message and consolidated logger initialization. You can now control the log level - for example suppress informational messages from Dash with `app.logger.setLevel(logging.WARNING)`.
diff --git a/dash/dependencies.py b/dash/dependencies.py
index 3c72d3867b..857b19f877 100644
--- a/dash/dependencies.py
+++ b/dash/dependencies.py
@@ -156,7 +156,7 @@ def handle_callback_args(args, kwargs):
     """Split args into outputs, inputs and states"""
     prevent_initial_call = kwargs.get("prevent_initial_call", None)
     if prevent_initial_call is None and args and isinstance(args[-1], bool):
-        prevent_initial_call = args.pop()
+        args, prevent_initial_call = args[:-1], args[-1]
 
     # flatten args, to support the older syntax where outputs, inputs, and states
     # each needed to be in their own list
diff --git a/requires-testing.txt b/requires-testing.txt
index 1aa667c03d..1662b98057 100644
--- a/requires-testing.txt
+++ b/requires-testing.txt
@@ -6,6 +6,7 @@ pytest-mock==2.0.0;python_version=="2.7"
 lxml==4.5.0
 selenium==3.141.0
 percy==2.0.2
+cryptography==3.0
 requests[security]==2.21.0
 beautifulsoup4==4.8.2
 waitress==1.4.3
diff --git a/tests/integration/callbacks/test_prevent_initial.py b/tests/integration/callbacks/test_prevent_initial.py
index adcef5b43e..8dba936145 100644
--- a/tests/integration/callbacks/test_prevent_initial.py
+++ b/tests/integration/callbacks/test_prevent_initial.py
@@ -333,3 +333,21 @@ def test_cbpi003_multi_outputs(flavor, dash_duo):
     dash_duo.wait_for_text_to_equal("#c", "BlueCheese")
     dash_duo.wait_for_text_to_equal("#b", "Cheese")
     dash_duo.wait_for_text_to_equal("#a", "Blue")
+
+
+def test_cbpi004_positional_arg(dash_duo):
+    app = dash.Dash(__name__)
+    app.layout = html.Div([html.Button("click", id="btn"), html.Div(id="out")])
+
+    @app.callback(Output("out", "children"), Input("btn", "n_clicks"), True)
+    def f(n):
+        return n
+
+    dash_duo.start_server(app)
+    dash_duo._wait_for_callbacks()
+
+    dash_duo.wait_for_text_to_equal("#out", "")
+
+    dash_duo.find_element("#btn").click()
+
+    dash_duo.wait_for_text_to_equal("#out", "1")
diff --git a/tests/integration/callbacks/test_validation.py b/tests/integration/callbacks/test_validation.py
index 61acaae0f9..d049e21be3 100644
--- a/tests/integration/callbacks/test_validation.py
+++ b/tests/integration/callbacks/test_validation.py
@@ -193,3 +193,33 @@ def o2(i, s):
     dash_duo.start_server(app)
     dash_duo.wait_for_text_to_equal("#out1", "1: High")
     dash_duo.wait_for_text_to_equal("#out2", "2: High")
+
+
+def test_cbva005_tuple_args(dash_duo):
+    app = Dash(__name__)
+    app.layout = html.Div(
+        [
+            html.Div("Yo", id="in1"),
+            html.Div("lo", id="in2"),
+            html.Div(id="out1"),
+            html.Div(id="out2"),
+        ]
+    )
+
+    @app.callback(
+        Output("out1", "children"), (Input("in1", "children"), Input("in2", "children"))
+    )
+    def f(i1, i2):
+        return "1: " + i1 + i2
+
+    @app.callback(
+        (Output("out2", "children"),),
+        Input("in1", "children"),
+        (State("in2", "children"),),
+    )
+    def g(i1, i2):
+        return ("2: " + i1 + i2,)
+
+    dash_duo.start_server(app)
+    dash_duo.wait_for_text_to_equal("#out1", "1: Yolo")
+    dash_duo.wait_for_text_to_equal("#out2", "2: Yolo")
diff --git a/tests/integration/renderer/test_request_hooks.py b/tests/integration/renderer/test_request_hooks.py
new file mode 100644
index 0000000000..5c7c574ad4
--- /dev/null
+++ b/tests/integration/renderer/test_request_hooks.py
@@ -0,0 +1,190 @@
+import json
+
+import dash_html_components as html
+import dash_core_components as dcc
+from dash import Dash
+from dash.dependencies import Output, Input
+
+
+def test_rdrh001_request_hooks(dash_duo):
+    app = Dash(__name__)
+
+    app.index_string = """<!DOCTYPE html>
+    <html>
+        <head>
+            {%metas%}
+            <title>{%title%}</title>
+            {%favicon%}
+            {%css%}
+        </head>
+        <body>
+            <div>Testing custom DashRenderer</div>
+            {%app_entry%}
+            <footer>
+                {%config%}
+                {%scripts%}
+                <script id="_dash-renderer" type"application/json">
+                    const renderer = new DashRenderer({
+                        request_pre: (payload) => {
+                            var output = document.getElementById('output-pre')
+                            var outputPayload = document.getElementById('output-pre-payload')
+                            if(output) {
+                                output.innerHTML = 'request_pre changed this text!';
+                            }
+                            if(outputPayload) {
+                                outputPayload.innerHTML = JSON.stringify(payload);
+                            }
+                        },
+                        request_post: (payload, response) => {
+                            var output = document.getElementById('output-post')
+                            var outputPayload = document.getElementById('output-post-payload')
+                            var outputResponse = document.getElementById('output-post-response')
+                            if(output) {
+                                output.innerHTML = 'request_post changed this text!';
+                            }
+                            if(outputPayload) {
+                                outputPayload.innerHTML = JSON.stringify(payload);
+                            }
+                            if(outputResponse) {
+                                outputResponse.innerHTML = JSON.stringify(response);
+                            }
+                        }
+                    })
+                </script>
+            </footer>
+            <div>With request hooks</div>
+        </body>
+    </html>"""
+
+    app.layout = html.Div(
+        [
+            dcc.Input(id="input", value="initial value"),
+            html.Div(
+                html.Div(
+                    [
+                        html.Div(id="output-1"),
+                        html.Div(id="output-pre"),
+                        html.Div(id="output-pre-payload"),
+                        html.Div(id="output-post"),
+                        html.Div(id="output-post-payload"),
+                        html.Div(id="output-post-response"),
+                    ]
+                )
+            ),
+        ]
+    )
+
+    @app.callback(Output("output-1", "children"), [Input("input", "value")])
+    def update_output(value):
+        return value
+
+    dash_duo.start_server(app)
+
+    _in = dash_duo.find_element("#input")
+    dash_duo.clear_input(_in)
+
+    _in.send_keys("fire request hooks")
+
+    dash_duo.wait_for_text_to_equal("#output-1", "fire request hooks")
+    dash_duo.wait_for_text_to_equal("#output-pre", "request_pre changed this text!")
+    dash_duo.wait_for_text_to_equal("#output-post", "request_post changed this text!")
+
+    assert json.loads(dash_duo.find_element("#output-pre-payload").text) == {
+        "output": "output-1.children",
+        "outputs": {"id": "output-1", "property": "children"},
+        "changedPropIds": ["input.value"],
+        "inputs": [{"id": "input", "property": "value", "value": "fire request hooks"}],
+    }
+
+    assert json.loads(dash_duo.find_element("#output-post-payload").text) == {
+        "output": "output-1.children",
+        "outputs": {"id": "output-1", "property": "children"},
+        "changedPropIds": ["input.value"],
+        "inputs": [{"id": "input", "property": "value", "value": "fire request hooks"}],
+    }
+
+    assert json.loads(dash_duo.find_element("#output-post-response").text) == {
+        "output-1": {"children": "fire request hooks"}
+    }
+
+    dash_duo.percy_snapshot(name="request-hooks render")
+
+
+def test_rdrh002_with_custom_renderer_interpolated(dash_duo):
+
+    renderer = """
+        <script id="_dash-renderer" type="application/javascript">
+            console.log('firing up a custom renderer!')
+            const renderer = new DashRenderer({
+                request_pre: () => {
+                    var output = document.getElementById('output-pre')
+                    if(output) {
+                        output.innerHTML = 'request_pre was here!';
+                    }
+                },
+                request_post: () => {
+                    var output = document.getElementById('output-post')
+                    if(output) {
+                        output.innerHTML = 'request_post!!!';
+                    }
+                }
+            })
+        </script>
+    """
+
+    class CustomDash(Dash):
+        def interpolate_index(self, **kwargs):
+            return """<!DOCTYPE html>
+            <html>
+                <head>
+                    <title>My App</title>
+                </head>
+                <body>
+
+                    <div id="custom-header">My custom header</div>
+                    {app_entry}
+                    {config}
+                    {scripts}
+                    {renderer}
+                    <div id="custom-footer">My custom footer</div>
+                </body>
+            </html>""".format(
+                app_entry=kwargs["app_entry"],
+                config=kwargs["config"],
+                scripts=kwargs["scripts"],
+                renderer=renderer,
+            )
+
+    app = CustomDash()
+
+    app.layout = html.Div(
+        [
+            dcc.Input(id="input", value="initial value"),
+            html.Div(
+                html.Div(
+                    [
+                        html.Div(id="output-1"),
+                        html.Div(id="output-pre"),
+                        html.Div(id="output-post"),
+                    ]
+                )
+            ),
+        ]
+    )
+
+    @app.callback(Output("output-1", "children"), [Input("input", "value")])
+    def update_output(value):
+        return value
+
+    dash_duo.start_server(app)
+
+    input1 = dash_duo.find_element("#input")
+    dash_duo.clear_input(input1)
+
+    input1.send_keys("fire request hooks")
+
+    dash_duo.wait_for_text_to_equal("#output-1", "fire request hooks")
+    assert dash_duo.find_element("#output-pre").text == "request_pre was here!"
+    assert dash_duo.find_element("#output-post").text == "request_post!!!"
+
+    dash_duo.percy_snapshot(name="request-hooks interpolated")
diff --git a/tests/integration/test_integration.py b/tests/integration/test_integration.py
index c9dbe1a657..fbd3ad4591 100644
--- a/tests/integration/test_integration.py
+++ b/tests/integration/test_integration.py
@@ -222,158 +222,6 @@ def create_layout():
     assert dash_duo.find_element("#a").text == "Hello World"
 
 
-def test_inin014_with_custom_renderer(dash_duo):
-    app = Dash(__name__)
-
-    app.index_string = """<!DOCTYPE html>
-    <html>
-        <head>
-            {%metas%}
-            <title>{%title%}</title>
-            {%favicon%}
-            {%css%}
-        </head>
-        <body>
-            <div>Testing custom DashRenderer</div>
-            {%app_entry%}
-            <footer>
-                {%config%}
-                {%scripts%}
-                <script id="_dash-renderer" type="application/javascript">
-                    console.log('firing up a custom renderer!')
-                    const renderer = new DashRenderer({
-                        request_pre: () => {
-                            var output = document.getElementById('output-pre')
-                            if(output) {
-                                output.innerHTML = 'request_pre!!!';
-                            }
-                        },
-                        request_post: () => {
-                            var output = document.getElementById('output-post')
-                            if(output) {
-                                output.innerHTML = 'request_post ran!';
-                            }
-                        }
-                    })
-                </script>
-            </footer>
-            <div>With request hooks</div>
-        </body>
-    </html>"""
-
-    app.layout = html.Div(
-        [
-            dcc.Input(id="input", value="initial value"),
-            html.Div(
-                html.Div(
-                    [
-                        html.Div(id="output-1"),
-                        html.Div(id="output-pre"),
-                        html.Div(id="output-post"),
-                    ]
-                )
-            ),
-        ]
-    )
-
-    @app.callback(Output("output-1", "children"), [Input("input", "value")])
-    def update_output(value):
-        return value
-
-    dash_duo.start_server(app)
-
-    input1 = dash_duo.find_element("#input")
-    dash_duo.clear_input(input1)
-
-    input1.send_keys("fire request hooks")
-
-    dash_duo.wait_for_text_to_equal("#output-1", "fire request hooks")
-    assert dash_duo.find_element("#output-pre").text == "request_pre!!!"
-    assert dash_duo.find_element("#output-post").text == "request_post ran!"
-
-    dash_duo.percy_snapshot(name="request-hooks intg")
-
-
-def test_inin015_with_custom_renderer_interpolated(dash_duo):
-
-    renderer = """
-        <script id="_dash-renderer" type="application/javascript">
-            console.log('firing up a custom renderer!')
-            const renderer = new DashRenderer({
-                request_pre: () => {
-                    var output = document.getElementById('output-pre')
-                    if(output) {
-                        output.innerHTML = 'request_pre was here!';
-                    }
-                },
-                request_post: () => {
-                    var output = document.getElementById('output-post')
-                    if(output) {
-                        output.innerHTML = 'request_post!!!';
-                    }
-                }
-            })
-        </script>
-    """
-
-    class CustomDash(Dash):
-        def interpolate_index(self, **kwargs):
-            return """<!DOCTYPE html>
-            <html>
-                <head>
-                    <title>My App</title>
-                </head>
-                <body>
-
-                    <div id="custom-header">My custom header</div>
-                    {app_entry}
-                    {config}
-                    {scripts}
-                    {renderer}
-                    <div id="custom-footer">My custom footer</div>
-                </body>
-            </html>""".format(
-                app_entry=kwargs["app_entry"],
-                config=kwargs["config"],
-                scripts=kwargs["scripts"],
-                renderer=renderer,
-            )
-
-    app = CustomDash()
-
-    app.layout = html.Div(
-        [
-            dcc.Input(id="input", value="initial value"),
-            html.Div(
-                html.Div(
-                    [
-                        html.Div(id="output-1"),
-                        html.Div(id="output-pre"),
-                        html.Div(id="output-post"),
-                    ]
-                )
-            ),
-        ]
-    )
-
-    @app.callback(Output("output-1", "children"), [Input("input", "value")])
-    def update_output(value):
-        return value
-
-    dash_duo.start_server(app)
-
-    input1 = dash_duo.find_element("#input")
-    dash_duo.clear_input(input1)
-
-    input1.send_keys("fire request hooks")
-
-    dash_duo.wait_for_text_to_equal("#output-1", "fire request hooks")
-    assert dash_duo.find_element("#output-pre").text == "request_pre was here!"
-    assert dash_duo.find_element("#output-post").text == "request_post!!!"
-
-    dash_duo.percy_snapshot(name="request-hooks interpolated")
-
-
 def test_inin017_late_component_register(dash_duo):
     app = Dash()
 
diff --git a/tests/integration/test_render.py b/tests/integration/test_render.py
index 1a79090323..f54d123bc1 100644
--- a/tests/integration/test_render.py
+++ b/tests/integration/test_render.py
@@ -2,8 +2,6 @@
 import time
 import json
 from multiprocessing import Value
-from selenium.webdriver.common.action_chains import ActionChains
-from selenium.webdriver.common.keys import Keys
 from selenium.webdriver.common.by import By
 from selenium.webdriver.support.ui import WebDriverWait
 from selenium.webdriver.support import expected_conditions as EC
@@ -779,126 +777,6 @@ def update_output(*args):
         self.assertEqual(call_count.value, 4)
         self.percy_snapshot("button-2 click again")
 
-    def test_request_hooks(self):
-        app = Dash(__name__)
-
-        app.index_string = """<!DOCTYPE html>
-        <html>
-            <head>
-                {%metas%}
-                <title>{%title%}</title>
-                {%favicon%}
-                {%css%}
-            </head>
-            <body>
-                <div>Testing custom DashRenderer</div>
-                {%app_entry%}
-                <footer>
-                    {%config%}
-                    {%scripts%}
-                    <script id="_dash-renderer" type"application/json">
-                        const renderer = new DashRenderer({
-                            request_pre: (payload) => {
-                                var output = document.getElementById('output-pre')
-                                var outputPayload = document.getElementById('output-pre-payload')
-                                if(output) {
-                                    output.innerHTML = 'request_pre changed this text!';
-                                }
-                                if(outputPayload) {
-                                    outputPayload.innerHTML = JSON.stringify(payload);
-                                }
-                            },
-                            request_post: (payload, response) => {
-                                var output = document.getElementById('output-post')
-                                var outputPayload = document.getElementById('output-post-payload')
-                                var outputResponse = document.getElementById('output-post-response')
-                                if(output) {
-                                    output.innerHTML = 'request_post changed this text!';
-                                }
-                                if(outputPayload) {
-                                    outputPayload.innerHTML = JSON.stringify(payload);
-                                }
-                                if(outputResponse) {
-                                    outputResponse.innerHTML = JSON.stringify(response);
-                                }
-                            }
-                        })
-                    </script>
-                </footer>
-                <div>With request hooks</div>
-            </body>
-        </html>"""
-
-        app.layout = html.Div(
-            [
-                dcc.Input(id="input", value="initial value"),
-                html.Div(
-                    html.Div(
-                        [
-                            html.Div(id="output-1"),
-                            html.Div(id="output-pre"),
-                            html.Div(id="output-pre-payload"),
-                            html.Div(id="output-post"),
-                            html.Div(id="output-post-payload"),
-                            html.Div(id="output-post-response"),
-                        ]
-                    )
-                ),
-            ]
-        )
-
-        @app.callback(Output("output-1", "children"), [Input("input", "value")])
-        def update_output(value):
-            return value
-
-        self.startServer(app)
-
-        input1 = self.wait_for_element_by_css_selector("#input")
-        initialValue = input1.get_attribute("value")
-
-        action = ActionChains(self.driver)
-        action.click(input1)
-        action = action.send_keys(Keys.BACKSPACE * len(initialValue))
-
-        action.send_keys("fire request hooks").perform()
-
-        self.wait_for_text_to_equal("#output-1", "fire request hooks")
-        self.wait_for_text_to_equal("#output-pre", "request_pre changed this text!")
-        self.wait_for_text_to_equal("#output-post", "request_post changed this text!")
-        pre_payload = self.wait_for_element_by_css_selector("#output-pre-payload").text
-        post_payload = self.wait_for_element_by_css_selector(
-            "#output-post-payload"
-        ).text
-        post_response = self.wait_for_element_by_css_selector(
-            "#output-post-response"
-        ).text
-        self.assertEqual(
-            json.loads(pre_payload),
-            {
-                "output": "output-1.children",
-                "outputs": {"id": "output-1", "property": "children"},
-                "changedPropIds": ["input.value"],
-                "inputs": [
-                    {"id": "input", "property": "value", "value": "fire request hooks"}
-                ],
-            },
-        )
-        self.assertEqual(
-            json.loads(post_payload),
-            {
-                "output": "output-1.children",
-                "outputs": {"id": "output-1", "property": "children"},
-                "changedPropIds": ["input.value"],
-                "inputs": [
-                    {"id": "input", "property": "value", "value": "fire request hooks"}
-                ],
-            },
-        )
-        self.assertEqual(
-            json.loads(post_response), {"output-1": {"children": "fire request hooks"}}
-        )
-        self.percy_snapshot(name="request-hooks render")
-
     def test_graphs_in_tabs_do_not_share_state(self):
         app = Dash()