diff --git a/jenkins-dendron-haproxy-postgres.sh b/jenkins-dendron-haproxy-postgres.sh
index d64b2d2c9de0368b6aebb55a847c7450bb15aca6..2f6544e22c4df5338bc18ee16ee4c1216dd30c38 100755
--- a/jenkins-dendron-haproxy-postgres.sh
+++ b/jenkins-dendron-haproxy-postgres.sh
@@ -17,6 +17,7 @@ export HAPROXY_BIN=/home/haproxy/haproxy-1.6.11/haproxy
 ./sytest/jenkins/prep_sytest_for_postgres.sh
 
 ./sytest/jenkins/install_and_run.sh \
+    --python $WORKSPACE/.tox/bin/python \
     --synapse-directory $WORKSPACE \
     --dendron $WORKSPACE/dendron/bin/dendron \
     --haproxy \
diff --git a/jenkins-dendron-postgres.sh b/jenkins-dendron-postgres.sh
index 37ae746f4bb48c56b8f83e07f3b4cd68b1a48497..bec6a72152c81b74c3f329ad1d8c60480261d08a 100755
--- a/jenkins-dendron-postgres.sh
+++ b/jenkins-dendron-postgres.sh
@@ -15,5 +15,6 @@ export SYNAPSE_CACHE_FACTOR=1
 ./sytest/jenkins/prep_sytest_for_postgres.sh
 
 ./sytest/jenkins/install_and_run.sh \
+    --python $WORKSPACE/.tox/bin/python \
     --synapse-directory $WORKSPACE \
     --dendron $WORKSPACE/dendron/bin/dendron \
diff --git a/jenkins-postgres.sh b/jenkins-postgres.sh
index f2ca8ccdff30cb06761b4b44e4e868c181bd63cf..8b38d7418d07a64fd18c586b8c7b466d06f76e9c 100755
--- a/jenkins-postgres.sh
+++ b/jenkins-postgres.sh
@@ -14,4 +14,5 @@ export SYNAPSE_CACHE_FACTOR=1
 ./sytest/jenkins/prep_sytest_for_postgres.sh
 
 ./sytest/jenkins/install_and_run.sh \
+    --python $WORKSPACE/.tox/bin/python \
     --synapse-directory $WORKSPACE \
diff --git a/jenkins-sqlite.sh b/jenkins-sqlite.sh
index 84613d979c665aead6d1e45a03a1d2c419ed2182..d20c6da6455d549c280df1342bc134c4ac5b474a 100755
--- a/jenkins-sqlite.sh
+++ b/jenkins-sqlite.sh
@@ -12,4 +12,5 @@ export SYNAPSE_CACHE_FACTOR=1
 ./jenkins/clone.sh sytest https://github.com/matrix-org/sytest.git
 
 ./sytest/jenkins/install_and_run.sh \
+    --python $WORKSPACE/.tox/bin/python \
     --synapse-directory $WORKSPACE \