diff --git a/.circleci/config.yml b/.circleci/config.yml
index 6ad5add5b4f2fa0340907e3e1fd9559ce95df177..3fe7c7630832fb9e47fb8a214723f72827f9b9e2 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -21,8 +21,8 @@ aliases:
       command: |
         virtualenv venv
         . venv/bin/activate
-        pip install --upgrade certifi pip pip-tools
-        pip-sync ${PIP_SYNC_REQUIREMENTS}
+        pip install --upgrade certifi pip
+        pip install ${PIP_REQUIREMENTS}
 
 jobs:
   documentation:
@@ -30,7 +30,7 @@ jobs:
       - image: "circleci/python:3.7"
 
     environment:
-      PIP_SYNC_REQUIREMENTS: "docs/requirements.txt"
+      PIP_REQUIREMENTS: "-r docs/requirements.txt"
 
     steps:
       - "checkout"
@@ -52,7 +52,7 @@ jobs:
       - image: "circleci/python:2.7"
 
     environment:
-      PIP_SYNC_REQUIREMENTS: "requirements.txt requirements-tests.txt"
+      PIP_REQUIREMENTS: "-r requirements.txt -r requirements-tests.txt"
       ZKAPAUTHORIZER_HYPOTHESIS_PROFILE: "ci"
 
     steps: