diff --git a/runtests.sh b/runtests.sh
index b6f62a72..05723cc4 100755
--- a/runtests.sh
+++ b/runtests.sh
@@ -2,4 +2,4 @@
 # system should be in "America/Los_Angeles" timezone for all tests to pass
 # ensure no local plugin parsers are installed for all tests to pass
 
-python3 -m unittest -v
+TZ=America/Los_Angeles python3 -m unittest -v