diff --git a/requirements-dev.txt b/requirements-dev.txt
index 82e7130..a694690 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -29,7 +29,7 @@ mypy-extensions==0.4.3    # via mypy
 mypy==0.770               # via -r requirements-dev.in
 packaging==19.2           # via pytest, tox
 pathspec==0.6.0           # via black
-pip-tools==4.4.0          # via -r requirements-dev.in
+pip-tools==5.1.2          # 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
@@ -59,4 +59,5 @@ webencodings==0.5.1       # via bleach
 wrapt==1.11.2             # via astroid
 
 # The following packages are considered to be unsafe in a requirements file:
+# pip
 # setuptools