diff --git a/ci_scripts/run-rust-test.sh b/ci_scripts/run-rust-test.sh
index 5a8e20c7d..b53200625 100755
--- a/ci_scripts/run-rust-test.sh
+++ b/ci_scripts/run-rust-test.sh
@@ -32,9 +32,9 @@ if [[ $NORUN == "1" ]]; then
     export CARGO_SUBCMD="build"
 else
     export CARGO_SUBCMD="test --all"
-    export OPT="${OPT} "
-    export OPT_RELEASE="${OPT_RELEASE} "
-    export OPT_RELEASE_IGNORED="${OPT_RELEASE} -- --ignored"
+    export OPT="-j1 ${OPT} "
+    export OPT_RELEASE="-j2 ${OPT_RELEASE} "
+    export OPT_RELEASE_IGNORED="-j2 ${OPT_RELEASE} -- --ignored"
 fi
 
 # Run all the test configurations: