diff --git a/Pipfile b/Pipfile
index 6da7fe38c..1fd9b869c 100644
--- a/Pipfile
+++ b/Pipfile
@@ -26,7 +26,7 @@ uvicorn = "*"
 
 [packages]
 starlette = "==0.11.1"
-pydantic = "==0.18.2"
+pydantic = "==0.21.0"
 
 [requires]
 python_version = "3.6"
diff --git a/Pipfile.lock b/Pipfile.lock
index 1240b40cf..839342b1b 100644
--- a/Pipfile.lock
+++ b/Pipfile.lock
@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "f1f1b7fb88822fcf89e5073263c5a42234fa68d18ce0b1b82e4dd926bcdf12e9"
+            "sha256": "676c6ae13691eef64abe6638f833cb8a330612521d3fad08718b240328b4877a"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -26,11 +26,11 @@
         },
         "pydantic": {
             "hashes": [
-                "sha256:9f023811b6cefd203c5fd8fd15a4152f04e79e531b8f676ab1244dfe06ce8024",
-                "sha256:edbb08b561feda505374c0f25e4b54466a0a0c702ed6b2efaabdc3890d1a82e7"
+                "sha256:93fa585402e7c8c01623ea8af6ca23363e8b4c6a020b7a2de9e99fa29d642d50",
+                "sha256:eb441dd50779347a450494c437db3ecbb13c1f3854497df879662782af516c5c"
             ],
             "index": "pypi",
-            "version": "==0.18.2"
+            "version": "==0.21.0"
         },
         "starlette": {
             "hashes": [
@@ -86,11 +86,11 @@
         },
         "black": {
             "hashes": [
-                "sha256:817243426042db1d36617910df579a54f1afd659adb96fc5032fcf4b36209739",
-                "sha256:e030a9a28f542debc08acceb273f228ac422798e5215ba2a791a6ddeaaca22a5"
+                "sha256:09a9dcb7c46ed496a9850b76e4e825d6049ecd38b611f1224857a79bd985a8cf",
+                "sha256:68950ffd4d9169716bcb8719a56c07a2f4485354fec061cdd5910aa07369731c"
             ],
             "index": "pypi",
-            "version": "==18.9b0"
+            "version": "==19.3b0"
         },
         "bleach": {
             "hashes": [
@@ -101,10 +101,10 @@
         },
         "certifi": {
             "hashes": [
-                "sha256:47f9c83ef4c0c621eaef743f133f09fa8a74a9b75f037e8624f83bd1b6626cb7",
-                "sha256:993f830721089fef441cdfeb4b2c8c9df86f0c63239f06bd025a76a7daddb033"
+                "sha256:59b7658e26ca9c7339e00f8f4636cdfe59d34fa37b9b04f6f9e9926b3cece1a5",
+                "sha256:b26104d6835d1f5e49452a26eb2ff87fe7090b89dfcaee5ea2212697e1e1d7ae"
             ],
-            "version": "==2018.11.29"
+            "version": "==2019.3.9"
         },
         "chardet": {
             "hashes": [
@@ -156,10 +156,10 @@
         },
         "decorator": {
             "hashes": [
-                "sha256:33cd704aea07b4c28b3eb2c97d288a06918275dac0ecebdaf1bc8a48d98adb9e",
-                "sha256:cabb249f4710888a2fc0e13e9a16c343d932033718ff62e1e9bc93a9d3a9122b"
+                "sha256:86156361c50488b84a3f148056ea716ca587df2f0de1d34750d35c21312725de",
+                "sha256:f069f3a01830ca754ba5258fde2278454a0b5b79e0d7f5c13b3b97e57d4acff6"
             ],
-            "version": "==4.3.2"
+            "version": "==4.4.0"
         },
         "defusedxml": {
             "hashes": [
@@ -224,7 +224,6 @@
             "hashes": [
                 "sha256:e00cbd7ba01ff748e494248183abc6e153f49181169d8a3d41bb49132ca01dfc"
             ],
-            "markers": "sys_platform != 'win32' and sys_platform != 'cygwin' and platform_python_implementation != 'pypy'",
             "version": "==0.0.13"
         },
         "idna": {
@@ -265,11 +264,11 @@
         },
         "isort": {
             "hashes": [
-                "sha256:38a74a5ccf3a15a7a99f975071164f48d4d10eed4154879009c18e6e8933e5aa",
-                "sha256:abbb2684aa234d5eb8a67ef36d4aa62ea080d46c2eba36ad09e2990ae52e4305"
+                "sha256:18c796c2cd35eb1a1d3f012a214a542790a1aed95e29768bdcb9f2197eccbd0b",
+                "sha256:96151fca2c6e736503981896495d344781b60d18bfda78dc11b290c6125ebdb6"
             ],
             "index": "pypi",
-            "version": "==4.3.13"
+            "version": "==4.3.15"
         },
         "jedi": {
             "hashes": [
@@ -445,10 +444,10 @@
         },
         "notebook": {
             "hashes": [
-                "sha256:9ca7f597ce4f5a24611c589fa320a7af2861f0ca1dc20839129c91ae354453fe",
-                "sha256:c5011449a1a6d9f96bf65c4c2d6713802a21125476312b39c99010ccd7a2e2ed"
+                "sha256:18a98858c0331fb65a60f2ebb6439f8c0c4defd14ca363731b6cabc7f61624b4",
+                "sha256:cc027a62be0f7756e0ef3d2d98458c4d7f4b3566449fb1a05891207f5bd9a1bf"
             ],
-            "version": "==5.7.5"
+            "version": "==5.7.6"
         },
         "pandocfilters": {
             "hashes": [
@@ -550,11 +549,11 @@
         },
         "pytest": {
             "hashes": [
-                "sha256:067a1d4bf827ffdd56ad21bd46674703fce77c5957f6c1eef731f6146bfcef1c",
-                "sha256:9687049d53695ad45cf5fdc7bbd51f0c49f1ea3ecfc4b7f3fde7501b541f17f4"
+                "sha256:592eaa2c33fae68c7d75aacf042efc9f77b27c08a6224a4f59beab8d9a420523",
+                "sha256:ad3ad5c450284819ecde191a654c09b0ec72257a2c711b9633d677c71c9850c4"
             ],
             "index": "pypi",
-            "version": "==4.3.0"
+            "version": "==4.3.1"
         },
         "pytest-cov": {
             "hashes": [
@@ -586,19 +585,19 @@
         },
         "pyyaml": {
             "hashes": [
-                "sha256:544a0050e76e9b60751c58617fa28c253ad5d23af2e5f0b1c250390bf90bb0df",
-                "sha256:594bf80477a58b6fd53e8b3f24ccf965c25eeeb6e05e4b1fb18c82c2d2090603",
-                "sha256:75e20ca689d0a2bf0c84f0e2028cc68ebef34b213fa66d73c410c53f870c49f4",
-                "sha256:994da68a1dc1050f290f8017f044172360b608c0f2562b47645ecc69d7a61c0a",
-                "sha256:ad902e00088c50bdced94a57b819c24fdadaeaed5494df7a9a67d63774f210fd",
-                "sha256:b11aff75875ffc73541c4e4b1ac2f5e21717c1fc4396238943b9a44d962e74e1",
-                "sha256:bc733b5a9047c3e4848c0e80eeacfa6a799139242606410260c5450d665ea58c",
-                "sha256:d960c68931b96bb215f385baa8ef867b8ebac66af60fa06cc1008f963848c7ad",
-                "sha256:dd461c04e6a91e4eef7d5b75c1fc1c7013d3f8d354033b16526baadddd524079",
-                "sha256:e4d6b5d6218a06f3141189d75c93876dd525a6d15f1b00ef4f274726c93719f1",
-                "sha256:f3c386fa12415bde8a0162745c4badf98fe171c6dfd67e54831f05ec88feeebb"
+                "sha256:1adecc22f88d38052fb787d959f003811ca858b799590a5eaa70e63dca50308c",
+                "sha256:436bc774ecf7c103814098159fbb84c2715d25980175292c648f2da143909f95",
+                "sha256:460a5a4248763f6f37ea225d19d5c205677d8d525f6a83357ca622ed541830c2",
+                "sha256:5a22a9c84653debfbf198d02fe592c176ea548cccce47553f35f466e15cf2fd4",
+                "sha256:7a5d3f26b89d688db27822343dfa25c599627bc92093e788956372285c6298ad",
+                "sha256:9372b04a02080752d9e6f990179a4ab840227c6e2ce15b95e1278456664cf2ba",
+                "sha256:a5dcbebee834eaddf3fa7366316b880ff4062e4bcc9787b78c7fbb4a26ff2dd1",
+                "sha256:aee5bab92a176e7cd034e57f46e9df9a9862a71f8f37cad167c6fc74c65f5b4e",
+                "sha256:c51f642898c0bacd335fc119da60baae0824f2cde95b0330b56c0553439f0673",
+                "sha256:c68ea4d3ba1705da1e0d85da6684ac657912679a649e8868bd850d2c299cce13",
+                "sha256:e23d0cc5299223dcc37885dae624f382297717e459ea24053709675a976a3e19"
             ],
-            "version": "==5.1b5"
+            "version": "==5.1"
         },
         "pyzmq": {
             "hashes": [
@@ -661,10 +660,10 @@
         },
         "sqlalchemy": {
             "hashes": [
-                "sha256:11ead7047ff3f394ed0d4b62aded6c5d970a9b718e1dc6add9f5e79442cc5b14"
+                "sha256:781fb7b9d194ed3fc596b8f0dd4623ff160e3e825dd8c15472376a438c19598b"
             ],
             "index": "pypi",
-            "version": "==1.3.0"
+            "version": "==1.3.1"
         },
         "terminado": {
             "hashes": [
@@ -746,26 +745,25 @@
         },
         "uvicorn": {
             "hashes": [
-                "sha256:8d523d0a003a874245025295b0c1233a762402c0d4c3988017401c6b461c83e9"
+                "sha256:d700b65169820fc260f39402b7f966c178691daaa40cb376cad99d7cd737f772"
             ],
             "index": "pypi",
-            "version": "==0.5.1"
+            "version": "==0.7.0b1"
         },
         "uvloop": {
             "hashes": [
-                "sha256:198fe0c196056930ec6c4a0a878e531a66d15467ca7c74a875aa90271f0c6e3f",
-                "sha256:1c175f47d34b84e33c0e312f4987c927ea004afc3a5f05d2f0f610d71d0e4c89",
-                "sha256:1c47f197be8f0a3c651dd20be1e1bd43268186246f246d4e86c91e95a89e4865",
-                "sha256:3fd4943570d20e8cd4d9f0a3190ebd5cf040e5610b685e05c878128a11f7ad14",
-                "sha256:435e232869923fd2248e4ca0ad73e24a5b4debf40bed9dcde133cfe1bef98a7a",
-                "sha256:9cfdb966ae804c46b96c92207dfd2174935ffc70e706e42e1c94c60d16dbe860",
-                "sha256:a585781443eeb2edb858f8c08c503aac237a5f1bebf0c84ea8340cc337afa408",
-                "sha256:b296493e033846e46488a6aa227a75c790091f5ee5456ec637bb0badad1e8851",
-                "sha256:c684047c6cf6d697ba37872fb1b4489012ea91f3f802c8fbb9c367c4902e88dc",
-                "sha256:da5a59d8812188b57b5783c7fb78891d14dd1050b6259680e0dbd4253d7d0f64"
-            ],
-            "markers": "sys_platform != 'win32' and sys_platform != 'cygwin' and platform_python_implementation != 'pypy'",
-            "version": "==0.12.1"
+                "sha256:0fcd894f6fc3226a962ee7ad895c4f52e3f5c3c55098e21efb17c071849a0573",
+                "sha256:2f31de1742c059c96cb76b91c5275b22b22b965c886ee1fced093fa27dde9e64",
+                "sha256:459e4649fcd5ff719523de33964aa284898e55df62761e7773d088823ccbd3e0",
+                "sha256:67867aafd6e0bc2c30a079603a85d83b94f23c5593b3cc08ec7e58ac18bf48e5",
+                "sha256:8c200457e6847f28d8bb91c5e5039d301716f5f2fce25646f5fb3fd65eda4a26",
+                "sha256:958906b9ca39eb158414fbb7d6b8ef1b7aee4db5c8e8e5d00fcbb69a1ce9dca7",
+                "sha256:ac1dca3d8f3ef52806059e81042ee397ac939e5a86c8a3cea55d6b087db66115",
+                "sha256:b284c22d8938866318e3b9d178142b8be316c52d16fcfe1560685a686718a021",
+                "sha256:c48692bf4587ce281d641087658eca275a5ad3b63c78297bbded96570ae9ce8f",
+                "sha256:fefc3b2b947c99737c348887db2c32e539160dcbeb7af9aa6b53db7a283538fe"
+            ],
+            "version": "==0.12.2"
         },
         "wcwidth": {
             "hashes": [
diff --git a/docs/src/application_configuration/tutorial002.py b/docs/src/application_configuration/tutorial002.py
index a45caf7bd..cf9ed7087 100644
--- a/docs/src/application_configuration/tutorial002.py
+++ b/docs/src/application_configuration/tutorial002.py
@@ -1,8 +1,6 @@
 from fastapi import FastAPI
 
-app = FastAPI(
-    openapi_url="/api/v1/openapi.json"
-)
+app = FastAPI(openapi_url="/api/v1/openapi.json")
 
 
 @app.get("/items/")
diff --git a/docs/src/application_configuration/tutorial003.py b/docs/src/application_configuration/tutorial003.py
index 464be5e35..ee09c7f37 100644
--- a/docs/src/application_configuration/tutorial003.py
+++ b/docs/src/application_configuration/tutorial003.py
@@ -1,9 +1,6 @@
 from fastapi import FastAPI
 
-app = FastAPI(
-    docs_url="/documentation",
-    redoc_url=None,
-)
+app = FastAPI(docs_url="/documentation", redoc_url=None)
 
 
 @app.get("/items/")
diff --git a/docs/src/bigger_applications/app/main.py b/docs/src/bigger_applications/app/main.py
index baec2aac0..4a12da434 100644
--- a/docs/src/bigger_applications/app/main.py
+++ b/docs/src/bigger_applications/app/main.py
@@ -1,7 +1,6 @@
 from fastapi import FastAPI
 
-from .routers import items
-from .routers import users
+from .routers import items, users
 
 app = FastAPI()
 
diff --git a/docs/tutorial/application-configuration.md b/docs/tutorial/application-configuration.md
index 955423aae..706ecd348 100644
--- a/docs/tutorial/application-configuration.md
+++ b/docs/tutorial/application-configuration.md
@@ -27,7 +27,7 @@ But you can configure it with the parameter `openapi_url`.
 
 For example, to set it to be served at `/api/v1/openapi.json`:
 
-```Python hl_lines="4"
+```Python hl_lines="3"
 {!./src/application_configuration/tutorial002.py!}
 ```
 
@@ -46,6 +46,6 @@ You can configure the two documentation user interfaces included:
 
 For example, to set Swagger UI to be served at `/documentation` and disable ReDoc:
 
-```Python hl_lines="4 5"
+```Python hl_lines="3"
 {!./src/application_configuration/tutorial003.py!}
 ```
diff --git a/docs/tutorial/bigger-applications.md b/docs/tutorial/bigger-applications.md
index e8a23613d..611c848bd 100644
--- a/docs/tutorial/bigger-applications.md
+++ b/docs/tutorial/bigger-applications.md
@@ -119,7 +119,7 @@ This will be the main file in your application that ties everything together.
 
 You import and create a `FastAPI` class as normally:
 
-```Python hl_lines="1 6"
+```Python hl_lines="1 5"
 {!./src/bigger_applications/app/main.py!}
 ```
 
@@ -129,7 +129,7 @@ But this time we are not adding *path operations* directly with the `FastAPI` `a
 
 We import the other submodules that have `APIRouter`s:
 
-```Python hl_lines="3 4"
+```Python hl_lines="3"
 {!./src/bigger_applications/app/main.py!}
 ```
 
@@ -141,21 +141,21 @@ As the file `app/routers/items.py` is part of the same Python package, we can im
 The section:
 
 ```Python
-from .routers import items
+from .routers import items, users
 ```
 
 Means:
 
 * Starting in the same package that this module (the file `app/main.py`) lives in (the directory `app/`)...
 * look for the subpackage `routers` (the directory at `app/routers/`)...
-* and from it, import the submodule `items` (the file at `app/routers/items.py`)...
+* and from it, import the submodule `items` (the file at `app/routers/items.py`) and `users` (the file at `app/routers/users.py`)...
 
-The module `items` will have a variable `router` (`items.router`). This is the same one we created in the file `app/routers/items.py`. It's an `APIRouter`.
+The module `items` will have a variable `router` (`items.router`). This is the same one we created in the file `app/routers/items.py`. It's an `APIRouter`. The same for the module `users`.
 
-We could also import it like:
+We could also import them like:
 
 ```Python
-from app.routers import items
+from app.routers import items, users
 ```
 
 !!! info
@@ -183,7 +183,7 @@ The `router` from `users` would overwrite the one from `items` and we wouldn't b
 
 So, to be able to use both of them in the same file, we import the submodules directly:
 
-```Python hl_lines="3 4"
+```Python hl_lines="3"
 {!./src/bigger_applications/app/main.py!}
 ```
 
diff --git a/fastapi/encoders.py b/fastapi/encoders.py
index 07e3c3dfb..ac3b317c6 100644
--- a/fastapi/encoders.py
+++ b/fastapi/encoders.py
@@ -1,6 +1,6 @@
 from enum import Enum
 from types import GeneratorType
-from typing import Any, Set
+from typing import Any, List, Set
 
 from pydantic import BaseModel
 from pydantic.json import ENCODERS_BY_TYPE
@@ -70,7 +70,7 @@ def jsonable_encoder(
                 )
             )
         return encoded_list
-    errors = []
+    errors: List[Exception] = []
     try:
         if custom_encoder and type(obj) in custom_encoder:
             encoder = custom_encoder[type(obj)]
diff --git a/pyproject.toml b/pyproject.toml
index a1c50745d..54c28c22f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,7 +20,7 @@ classifiers = [
 ]
 requires = [
     "starlette ==0.11.1",
-    "pydantic >=0.17,<=0.18.2"
+    "pydantic >=0.17,<=0.21.0"
 ]
 description-file = "README.md"
 requires-python = ">=3.6"
diff --git a/scripts/test.sh b/scripts/test.sh
index 2e5457075..e2e6d94c9 100755
--- a/scripts/test.sh
+++ b/scripts/test.sh
@@ -13,7 +13,7 @@ fi
 
 export PYTHONPATH=./docs/src
 pytest --cov=fastapi --cov=tests --cov=docs/src --cov-report=term-missing ${@}
-mypy fastapi --disallow-untyped-defs
+mypy fastapi --disallow-untyped-defs --follow-imports=skip
 if [ "${PYTHON_VERSION}" = '3.7' ]; then
     echo "Skipping 'black' on 3.7. See issue https://github.com/ambv/black/issues/494"
 else