diff --git a/benchmark/benchmarks/pairwise_loop.py b/benchmark/benchmarks/pairwise_loop.py
new file mode 100644
index 000000000..8f3fee434
--- /dev/null
+++ b/benchmark/benchmarks/pairwise_loop.py
@@ -0,0 +1,18 @@
+#from: http://jakevdp.github.com/blog/2012/08/24/numba-vs-cython/
+#setup: import numpy as np ; X = np.linspace(0,10,200).reshape(20,10)
+#run: pairwise_loop(X)
+
+#pythran export pairwise_loop(float [][])
+
+import numpy as np
+def pairwise_loop(X):
+    M, N = X.shape
+    D = np.empty((M,M))
+    for i in range(M):
+        for j in range(M):
+            d = 0.0
+            for k in range(N):
+                tmp = X[i,k] - X[j,k]
+                d += tmp * tmp
+            D[i,j] = np.sqrt(d)
+    return D
diff --git a/test/conftest.py b/test/conftest.py
index 877b501f2..81154ae62 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -55,11 +55,14 @@ def _display_driver_logs(browser, driver):
 
 
 class SeleniumWrapper:
-    def __init__(self, build_dir, server_port, server_hostname='127.0.0.1',
-                 server_log=None):
+    def __init__(self, server_port, server_hostname='127.0.0.1',
+                 server_log=None, build_dir=None):
         from selenium.webdriver.support.wait import WebDriverWait
         from selenium.common.exceptions import TimeoutException
 
+        if build_dir is None:
+            build_dir = BUILD_PATH
+
         driver = self.get_driver()
         wait = WebDriverWait(driver, timeout=20)
         if not (pathlib.Path(build_dir) / 'test.html').exists():
@@ -223,7 +226,10 @@ def web_server_secondary(request):
 
 
 @contextlib.contextmanager
-def spawn_web_server(build_dir):
+def spawn_web_server(build_dir=None):
+
+    if build_dir is None:
+        build_dir = BUILD_PATH
 
     tmp_dir = tempfile.mkdtemp()
     log_path = pathlib.Path(tmp_dir) / 'http-server.log'
@@ -312,7 +318,7 @@ def run_web_server(q, log_filepath, build_dir):
 if (__name__ == '__main__'
         and multiprocessing.current_process().name == 'MainProcess'
         and not hasattr(sys, "_pytest_session")):
-    with spawn_web_server(BUILD_PATH):
+    with spawn_web_server():
         # run forever
         while True:
             time.sleep(1)