diff --git a/.circleci/run-tests.sh b/.circleci/run-tests.sh
index 9b7091269..25427e221 100755
--- a/.circleci/run-tests.sh
+++ b/.circleci/run-tests.sh
@@ -4,7 +4,7 @@ TAHOE_LAFS_TOX_ENVIRONMENT=$1
 shift
 
 TAHOE_LAFS_TOX_ARGS=$1
-shift
+shift || :
 
 # Run the test suite as a non-root user.  This is the expected usage some
 # small areas of the test suite assume non-root privileges (such as unreadable
diff --git a/.circleci/setup-virtualenv.sh b/.circleci/setup-virtualenv.sh
index 97d7825d4..690609777 100755
--- a/.circleci/setup-virtualenv.sh
+++ b/.circleci/setup-virtualenv.sh
@@ -4,7 +4,7 @@ TAHOE_LAFS_TOX_ENVIRONMENT=$1
 shift
 
 TAHOE_LAFS_TOX_ARGS=$1
-shift
+shift || :
 
 # Set up the virtualenv as a non-root user so we can run the test suite as a
 # non-root user.  See below.