diff --git a/tools/env.sh b/tools/env.sh
index f31e842e..5b6de5f7 100755
--- a/tools/env.sh
+++ b/tools/env.sh
@@ -16,4 +16,4 @@ export LUNA_BUILD=ninja
 export LUNA_CMAKE_GENERATOR_NAME="Ninja"
 fi
 
-export LUNA_BUILD_DIR=$LUNA_ROOT/build/$LUNA_BUILD-$LUNA_ARCH
+export LUNA_BUILD_DIR=$LUNA_ROOT/build/${LUNA_BUILD_PREFIX:-""}$LUNA_BUILD-$LUNA_ARCH
diff --git a/tools/run-tests.sh b/tools/run-tests.sh
index f79a78c8..c1f827fe 100755
--- a/tools/run-tests.sh
+++ b/tools/run-tests.sh
@@ -1,6 +1,8 @@
 #!/usr/bin/env bash
 set -e
 
+export LUNA_BUILD_PREFIX="tests-"
+
 source $(dirname $0)/env.sh
 
 cd $LUNA_ROOT