diff --git a/test-pbio.sh b/test-pbio.sh
index 15ab980f6..931cc71a8 100755
--- a/test-pbio.sh
+++ b/test-pbio.sh
@@ -11,7 +11,7 @@ SCRIPT_DIR=$(dirname "$0")
 
 export PBIO_TEST_RESULTS_DIR="${SCRIPT_DIR}/lib/pbio/test/results"
 rm -rf "${PBIO_TEST_RESULTS_DIR:?}"/*
-make -s -C "${SCRIPT_DIR}/lib/pbio/test"
+make -s -C "${SCRIPT_DIR}/lib/pbio/test" -j$(nproc)
 
 ulimit -S -c unlimited