diff --git a/.circleci/config.yml b/.circleci/config.yml
index bcb3c0afec465b..3542b34fc7a31d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -49,11 +49,16 @@ jobs:
       - checkout
       - *restore_repo
       - run:
-          name: Check if yarn prettier was run
+          name: Export COMMIT_RANGE
           command: |
             # commit range between master and branch
             # CIRCLE_COMPARE_URL=https://github.com/org/repo/compare/sha1...sha1
-            COMMIT_RANGE=$(grep -oP "\w+\.\.\.\w+" <<< "$CIRCLE_COMPARE_URL")
+            # https://circleci.com/docs/2.0/env-vars/#setting-an-environment-variable-in-a-shell-command
+            echo 'export COMMIT_RANGE=$(grep -oP "\w+\.\.\.\w+" <<< "$CIRCLE_COMPARE_URL")' >> $BASH_ENV
+            source $BASH_ENV
+      - run:
+          name: Check if yarn prettier was run
+          command: |
             # Files changed on this branch
             CHANGED_FILES=$(git diff --name-only "$COMMIT_RANGE")
             # if we use an empty string as a pattern grep will match everything