diff --git a/tools/circle-upload-codecov.sh b/tools/circle-upload-codecov.sh
index 49ef48e583..a50f1cf334 100755
--- a/tools/circle-upload-codecov.sh
+++ b/tools/circle-upload-codecov.sh
@@ -2,15 +2,15 @@
 
 set -eo pipefail
 
-PLATFORM=`uname -m`
+PLATFORM=$(uname -m)
 [ $PLATFORM == "x86_64" ] && PLATFORM=linux
 BASE_URL="https://uploader.codecov.io/latest/$PLATFORM"
 
 # Source: https://docs.codecov.com/docs/codecov-uploader#integrity-checking-the-uploader
 curl https://keybase.io/codecovsecurity/pgp_keys.asc | gpg --no-default-keyring --keyring trustedkeys.gpg --import
-curl -Os "$BASE_URL/codecov"
-curl -Os "$BASE_URL/codecov.SHA256SUM"
-curl -Os "$BASE_URL/codecov.SHA256SUM.sig"
+curl -Os "${BASE_URL}/codecov"
+curl -Os "${BASE_URL}/codecov.SHA256SUM"
+curl -Os "${BASE_URL}/codecov.SHA256SUM.sig"
 gpgv codecov.SHA256SUM.sig codecov.SHA256SUM
 shasum -a 256 -c codecov.SHA256SUM
 
diff --git a/tools/circleci-upload-to-s3.sh b/tools/circleci-upload-to-s3.sh
index 40f60e7d58..db951a9d67 100755
--- a/tools/circleci-upload-to-s3.sh
+++ b/tools/circleci-upload-to-s3.sh
@@ -21,7 +21,7 @@ ls $CT_REPORTS
 if which aws ; then
     echo "aws tool ready"
 else
-    curl "https://awscli.amazonaws.com/awscli-exe-linux-`uname -m`.zip" -o "awscliv2.zip"
+    curl "https://awscli.amazonaws.com/awscli-exe-linux-$(uname -m).zip" -o "awscliv2.zip"
     unzip -q awscliv2.zip
     sudo ./aws/install
 fi