diff --git a/requirements-dev.txt b/requirements-dev.txt
index eaca6b9..25ddfa3 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -7,7 +7,7 @@
 appdirs==1.4.3            # via black
 astroid==2.3.3            # via pylint
 attrs==19.3.0             # via black, pytest
-black==19.10b0
+black==19.10b0            # via -r requirements-dev.in
 bleach==3.1.0             # via readme-renderer
 certifi==2019.11.28       # via requests
 cffi==1.13.2              # via cryptography
@@ -17,7 +17,7 @@ cryptography==2.8         # via secretstorage
 docutils==0.15.2          # via readme-renderer
 entrypoints==0.3          # via flake8
 filelock==3.0.12          # via tox
-flake8==3.7.9
+flake8==3.7.9             # via -r requirements-dev.in
 idna==2.8                 # via requests
 isort==4.3.21             # via pylint
 jeepney==0.4.1            # via secretstorage
@@ -26,10 +26,10 @@ lazy-object-proxy==1.4.3  # via astroid
 mccabe==0.6.1             # via flake8, pylint
 more-itertools==8.0.2     # via pytest
 mypy-extensions==0.4.3    # via mypy
-mypy==0.761
+mypy==0.761               # via -r requirements-dev.in
 packaging==19.2           # via pytest, tox
 pathspec==0.6.0           # via black
-pip-tools==4.4.0
+pip-tools==4.4.0          # via -r requirements-dev.in
 pkginfo==1.5.0.1          # via twine
 pluggy==0.13.1            # via pytest, tox
 py==1.8.0                 # via pytest, tox
@@ -37,19 +37,19 @@ pycodestyle==2.5.0        # via flake8
 pycparser==2.19           # via cffi
 pyflakes==2.1.1           # via flake8
 pygments==2.5.2           # via readme-renderer
-pylint==2.4.4
+pylint==2.4.4             # via -r requirements-dev.in
 pyparsing==2.4.5          # via packaging
-pytest==5.3.5
+pytest==5.3.5             # via -r requirements-dev.in
 readme-renderer==24.0     # via twine
 regex==2019.12.9          # via black
 requests-toolbelt==0.9.1  # via twine
 requests==2.22.0          # via requests-toolbelt, twine
 secretstorage==3.1.1      # via keyring
-six==1.13.0               # via astroid, bleach, cryptography, packaging, pip-tools, readme-renderer, tox
+six==1.14.0               # via astroid, bleach, cryptography, packaging, pip-tools, readme-renderer, tox
 toml==0.10.0              # via black, tox
-tox==3.14.3
+tox==3.15.1               # via -r requirements-dev.in
 tqdm==4.40.2              # via twine
-twine==3.1.1
+twine==3.1.1              # via -r requirements-dev.in
 typed-ast==1.4.0          # via black, mypy
 typing-extensions==3.7.4.1  # via mypy
 urllib3==1.25.7           # via requests