diff --git a/tootpaste.sh b/tootpaste.sh
index 778e424..726a1d1 100644
--- a/tootpaste.sh
+++ b/tootpaste.sh
@@ -14,12 +14,12 @@ DRY_RUN=${DRY_RUN:-true}
 TLS_EXPIRED_MAX_SEC=${TLS_EXPIRED_MAX_SEC:-1210000}
 # How many seconds to wait to connect to an instance already in error in the
 # past
-INSTANCE_LAST_CHANCE_TIMEOUT=30
+INSTANCE_LAST_CHANCE_TIMEOUT=${INSTANCE_LAST_CHANCE_TIMEOUT:-30}
 # How old media attachments have to be before getting removed
-MEDIA_REMOVE_DAYS=7
-CARDS_REMOVE_DAYS=15
+MEDIA_REMOVE_DAYS=${MEDIA_REMOVE_DAYS:-7}
+CARDS_REMOVE_DAYS=${CARDS_REMOVE_DAYS:-15}
 # How old unreferenced statuses have to be before getting removed
-STATUSES_REMOVE_DAYS=30
+STATUSES_REMOVE_DAYS=${STATUSES_REMOVE_DAYS:-30}
 # Path to logs files
 CULL_LOG=/tmp/$(mktemp tootpaste_XXX)
 TLS_EXPIRED_LOG=/tmp/$(mktemp tootpaste_XXX)