diff --git a/requirements.txt b/requirements.txt
index 8304fb8..8cec2b6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -14,11 +14,11 @@ cycler==0.10.0            # via matplotlib
 docutils==0.14            # via readme-renderer
 idna==2.8                 # via requests
 kiwisolver==1.0.1         # via matplotlib
-matplotlib==3.0.3
+matplotlib==3.0.3         # via -r requirements.in, sanitized-package
 numpy==1.16.2             # via matplotlib
-pip-tools==3.5.0
+pip-tools==3.5.0          # via -r requirements.in
 pkginfo==1.5.0.1          # via twine
-psutil==5.6.1             # via zproc
+psutil==5.6.6             # via zproc
 pygments==2.3.1           # via readme-renderer
 pyparsing==2.3.1          # via matplotlib
 python-dateutil==2.8.0    # via matplotlib
@@ -29,7 +29,7 @@ requests==2.21.0          # via requests-toolbelt, twine
 six==1.12.0               # via bleach, cycler, pip-tools, python-dateutil, readme-renderer
 tblib==1.3.2              # via zproc
 tqdm==4.31.1              # via twine
-twine==1.13.0
+twine==1.13.0             # via -r requirements.in
 urllib3==1.24.1           # via requests
 webencodings==0.5.1       # via bleach
-zproc==0.9.5
+zproc==0.9.5              # via -r requirements.in, sanitized-package