diff --git a/.circleci/config.yml b/.circleci/config.yml
index b36218b21e..16c079605f 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -22,10 +22,10 @@ jobs:
 
       - restore_cache:
           keys:
-          - v1-npm-base.trusty.1
+          - v1-npm-base.trusty-{{ checksum "package.json" }}-{{ checksum "yarn.lock" }}
       - restore_cache:
           keys:
-          - v1-venv-base.trusty.1
+          - v1-venv-base.trusty-{{ checksum "requirements/thumbor.txt" }}-{{ checksum "requirements/dev.txt" }}
 
       - run:
           name: install dependencies
@@ -51,11 +51,11 @@ jobs:
       - save_cache:
           paths:
             - /srv/zulip-npm-cache
-          key: v1-npm-base.trusty.1
+          key: v1-npm-base.trusty-{{ checksum "package.json" }}-{{ checksum "yarn.lock" }}
       - save_cache:
           paths:
             - /srv/zulip-venv-cache
-          key: v1-venv-base.trusty.1
+          key: v1-venv-base.trusty-{{ checksum "requirements/thumbor.txt" }}-{{ checksum "requirements/dev.txt" }}
       # TODO: in Travis we also cache ~/zulip-emoji-cache, ~/node, ~/misc
 
       # The moment of truth!  Run the tests.
@@ -103,10 +103,10 @@ jobs:
 
       - restore_cache:
           keys:
-          - v1-npm-base.xenial.1
+          - v1-npm-base.xenial-{{ checksum "package.json" }}-{{ checksum "yarn.lock" }}
       - restore_cache:
           keys:
-          - v1-venv-base.xenial.1
+          - v1-venv-base.xenial-{{ checksum "requirements/thumbor.txt" }}-{{ checksum "requirements/dev.txt" }}
 
       - run:
           name: install dependencies
@@ -118,11 +118,11 @@ jobs:
       - save_cache:
           paths:
             - /srv/zulip-npm-cache
-          key: v1-npm-base.xenial.1
+          key: v1-npm-base.xenial-{{ checksum "package.json" }}-{{ checksum "yarn.lock" }}
       - save_cache:
           paths:
             - /srv/zulip-venv-cache
-          key: v1-venv-base.xenial.1
+          key: v1-venv-base.xenial-{{ checksum "requirements/thumbor.txt" }}-{{ checksum "requirements/dev.txt" }}
 
       - run:
           name: run backend tests