diff --git a/qa/pull-tester/run-bitcoind-for-test.sh.in b/qa/pull-tester/run-bitcoind-for-test.sh.in
index e186bd7a23..67318e5a4c 100755
--- a/qa/pull-tester/run-bitcoind-for-test.sh.in
+++ b/qa/pull-tester/run-bitcoind-for-test.sh.in
@@ -9,7 +9,7 @@ mkdir -p "$DATADIR"/regtest
 touch "$DATADIR/regtest/debug.log"
 tail -q -n 1 -F "$DATADIR/regtest/debug.log" | grep -m 1 -q "Done loading" &
 WAITER=$!
-PORT=`expr 10000 + $BASHPID % 55536`
+PORT=`expr 10000 + $$ % 55536`
 "@abs_top_builddir@/src/bitcoind@EXEEXT@" -connect=0.0.0.0 -datadir="$DATADIR" -rpcuser=user -rpcpassword=pass -listen -keypool=3 -debug -debug=net -logtimestamps -port=$PORT -whitelist=127.0.0.1 -regtest -rpcport=`expr $PORT + 1` &
 BITCOIND=$!