diff --git a/jenkins.sh b/jenkins.sh
index e2bb706c7f..804bbd49f1 100755
--- a/jenkins.sh
+++ b/jenkins.sh
@@ -52,7 +52,7 @@ RUN_POSTGRES=""
 
 for port in $(($PORT_BASE + 1)) $(($PORT_BASE + 2)); do
     if psql synapse_jenkins_$port <<< ""; then
-        RUN_POSTGRES=$RUN_POSTGRES:$port
+        RUN_POSTGRES="$RUN_POSTGRES:$port"
         cat > localhost-$port/database.yaml << EOF
 name: psycopg2
 args:
@@ -62,7 +62,7 @@ EOF
 done
 
 # Run if both postgresql databases exist
-if test $RUN_POSTGRES = ":$(($PORT_BASE + 1)):$(($PORT_BASE + 2))"; then
+if test "$RUN_POSTGRES" = ":$(($PORT_BASE + 1)):$(($PORT_BASE + 2))"; then
     echo >&2 "Running sytest with PostgreSQL";
     $TOX_BIN/pip install psycopg2
     ./run-tests.pl --coverage -O tap --synapse-directory $WORKSPACE \