diff --git a/py/BUILD.bazel b/py/BUILD.bazel
index 25130dad0de7b..10e756a683bbe 100644
--- a/py/BUILD.bazel
+++ b/py/BUILD.bazel
@@ -50,8 +50,10 @@ py_library(
     imports = ["."],
     visibility = ["//visibility:public"],
     deps = [
-        "//third_party/py:certifi",
-        "//third_party/py:urllib3",
+        requirement("trio"),
+        requirement("trio_websocket"),
+        requirement("urllib3"),
+        requirement("certifi"),
     ],
 )
 
@@ -188,8 +190,6 @@ py_test_suite(
         requirement("pytest-trio"),
         requirement("sortedcontainers"),
         requirement("sniffio"),
-        requirement("trio"),
-        requirement("trio_websocket"),
         requirement("zipp"),
     ],
 )
@@ -241,8 +241,6 @@ py_test_suite(
         requirement("pytest-trio"),
         requirement("sortedcontainers"),
         requirement("sniffio"),
-        requirement("trio"),
-        requirement("trio_websocket"),
         requirement("zipp"),
     ],
 )
@@ -281,8 +279,6 @@ py_test_suite(
         requirement("pytest-trio"),
         requirement("sortedcontainers"),
         requirement("sniffio"),
-        requirement("trio"),
-        requirement("trio_websocket"),
         requirement("zipp"),
     ],
 )
@@ -321,8 +317,6 @@ py_test_suite(
         requirement("pytest-trio"),
         requirement("sortedcontainers"),
         requirement("sniffio"),
-        requirement("trio"),
-        requirement("trio_websocket"),
         requirement("zipp"),
     ],
 )
@@ -361,8 +355,6 @@ py_test_suite(
         requirement("pytest-trio"),
         requirement("sortedcontainers"),
         requirement("sniffio"),
-        requirement("trio"),
-        requirement("trio_websocket"),
         requirement("zipp"),
     ],
 )
@@ -403,8 +395,6 @@ py_test_suite(
         requirement("pytest-trio"),
         requirement("sortedcontainers"),
         requirement("sniffio"),
-        requirement("trio"),
-        requirement("trio_websocket"),
         requirement("zipp"),
     ],
 )
@@ -443,8 +433,6 @@ py_test_suite(
         requirement("pytest-trio"),
         requirement("sortedcontainers"),
         requirement("sniffio"),
-        requirement("trio"),
-        requirement("trio_websocket"),
         requirement("zipp"),
     ],
 )
@@ -484,8 +472,6 @@ py_test_suite(
         requirement("pytest-trio"),
         requirement("sortedcontainers"),
         requirement("sniffio"),
-        requirement("trio"),
-        requirement("trio_websocket"),
         requirement("zipp"),
     ],
 )
@@ -526,8 +512,6 @@ py_test_suite(
         requirement("pytest-trio"),
         requirement("sortedcontainers"),
         requirement("sniffio"),
-        requirement("trio"),
-        requirement("trio_websocket"),
         requirement("zipp"),
     ],
 )
@@ -568,8 +552,6 @@ py_test_suite(
         requirement("pytest-trio"),
         requirement("sortedcontainers"),
         requirement("sniffio"),
-        requirement("trio"),
-        requirement("trio_websocket"),
         requirement("zipp"),
     ],
 )
diff --git a/py/requirements.txt b/py/requirements.txt
index 114ac06a10009..2b71ab428108a 100644
--- a/py/requirements.txt
+++ b/py/requirements.txt
@@ -1,4 +1,5 @@
 attrs
+certifi
 dataclasses
 debugpy
 h11
@@ -19,4 +20,5 @@ sortedcontainers
 sniffio
 trio
 trio_websocket
+urllib3
 zipp
diff --git a/third_party/py/BUILD.bazel b/third_party/py/BUILD.bazel
index f79708cfd0253..cd7343670f3d2 100644
--- a/third_party/py/BUILD.bazel
+++ b/third_party/py/BUILD.bazel
@@ -13,83 +13,3 @@ py_import(
     ],
 )
 
-py_import(
-    name = "mock",
-    wheel = "mock-2.0.0-py2.py3-none-any.whl",
-    deps = [
-        ":pbr",
-        ":six",
-    ],
-)
-
-py_import(
-    name = "pbr",
-    wheel = "pbr-2.0.0-py2.py3-none-any.whl",
-)
-
-py_import(
-    name = "py",
-    wheel = "py-1.4.32-py2.py3-none-any.whl",
-)
-
-py_import(
-    name = "pytest",
-    visibility = [
-        "//visibility:public",
-    ],
-    wheel = "pytest-3.0.3-py2.py3-none-any.whl",
-    deps = [
-        ":py",
-        ":pytest-instafail",
-        ":pytest-mock",
-        #        ":pytest-timeout",
-        ":pytest-xdist",
-    ],
-)
-
-py_import(
-    name = "pytest-mock",
-    wheel = "pytest_mock-1.5.0-py2.py3-none-any.whl",
-    deps = [
-        "mock",
-    ],
-)
-
-py_import(
-    name = "pytest-instafail",
-    wheel = "pytest-instafail-0.3.0.tar.gz",
-)
-
-py_import(
-    name = "pytest-timeout",
-    wheel = "pytest_timeout-1.2.0-py2.py3-none-any.whl",
-)
-
-py_import(
-    name = "pytest-xdist",
-    wheel = "pytest-xdist-1.15.0.tar.gz",
-    deps = [
-        ":execnet",
-    ],
-)
-
-py_import(
-    name = "six",
-    wheel = "six-1.11.0.tar.gz",
-)
-
-py_import(
-    name = "urllib3",
-    visibility = [
-        "//visibility:public",
-    ],
-    wheel = "urllib3-1.23-py2.py3-none-any.whl",
-)
-
-py_import(
-    name = "certifi",
-    visibility = [
-        "//visibility:public",
-    ],
-    wheel = "certifi-2018.8.24-py2.py3-none-any.whl",
-)
diff --git a/third_party/py/certifi-2018.11.29.tar.gz b/third_party/py/certifi-2018.11.29.tar.gz
deleted file mode 100644
index 07ebdc7429c05..0000000000000
Binary files a/third_party/py/certifi-2018.11.29.tar.gz and /dev/null differ
diff --git a/third_party/py/certifi-2018.8.24-py2.py3-none-any.whl b/third_party/py/certifi-2018.8.24-py2.py3-none-any.whl
deleted file mode 100644
index 6955e65d6ef7b..0000000000000
Binary files a/third_party/py/certifi-2018.8.24-py2.py3-none-any.whl and /dev/null differ
diff --git a/third_party/py/pytest-3.0.3-py2.py3-none-any.whl b/third_party/py/pytest-3.0.3-py2.py3-none-any.whl
deleted file mode 100644
index 0de12e798b013..0000000000000
Binary files a/third_party/py/pytest-3.0.3-py2.py3-none-any.whl and /dev/null differ
diff --git a/third_party/py/pytest-instafail-0.3.0.tar.gz b/third_party/py/pytest-instafail-0.3.0.tar.gz
deleted file mode 100644
index 51af16f0938df..0000000000000
Binary files a/third_party/py/pytest-instafail-0.3.0.tar.gz and /dev/null differ
diff --git a/third_party/py/pytest-xdist-1.15.0.tar.gz b/third_party/py/pytest-xdist-1.15.0.tar.gz
deleted file mode 100644
index 2a4b8b3f85e00..0000000000000
Binary files a/third_party/py/pytest-xdist-1.15.0.tar.gz and /dev/null differ
diff --git a/third_party/py/pytest_mock-1.5.0-py2.py3-none-any.whl b/third_party/py/pytest_mock-1.5.0-py2.py3-none-any.whl
deleted file mode 100644
index 4f4a6446f614b..0000000000000
Binary files a/third_party/py/pytest_mock-1.5.0-py2.py3-none-any.whl and /dev/null differ
diff --git a/third_party/py/pytest_timeout-1.2.0-py2.py3-none-any.whl b/third_party/py/pytest_timeout-1.2.0-py2.py3-none-any.whl
deleted file mode 100644
index 400851fa89dbb..0000000000000
Binary files a/third_party/py/pytest_timeout-1.2.0-py2.py3-none-any.whl and /dev/null differ
diff --git a/third_party/py/urllib3-1.23-py2.py3-none-any.whl b/third_party/py/urllib3-1.23-py2.py3-none-any.whl
deleted file mode 100644
index a385e3c96713d..0000000000000
Binary files a/third_party/py/urllib3-1.23-py2.py3-none-any.whl and /dev/null differ
diff --git a/third_party/py/urllib3-1.24.1.tar.gz b/third_party/py/urllib3-1.24.1.tar.gz
deleted file mode 100644
index 41c61d30452d1..0000000000000
Binary files a/third_party/py/urllib3-1.24.1.tar.gz and /dev/null differ