diff --git a/ci/scripts/test.sh b/ci/scripts/test.sh
index 729b3837e93ba16c1ecec28a19573db64c25e52a..65adde1d2218949375cdf9a8e0c7d1637932f2fb 100644
--- a/ci/scripts/test.sh
+++ b/ci/scripts/test.sh
@@ -32,9 +32,12 @@ fi
 export PYTHONPATH="$INSTALL_DIR/lib/python2.7/site-packages"
 python -c 'import hysop; print hysop'
 
-$HYSOP_DIR/fields/tests/test_cartesian.sh
+# long backend dependent tests
 #python "$HYSOP_DIR/backend/device/codegen/kernels/tests/test_directional_advection.py"
 #python "$HYSOP_DIR/backend/device/codegen/kernels/tests/test_directional_remesh.py"
+
+python "$HYSOP_DIR/core/arrays/tests/test_array.py"
+$HYSOP_DIR/fields/tests/test_cartesian.sh
 python "$HYSOP_DIR/operator/tests/test_analytic.py"
 python "$HYSOP_DIR/operator/tests/test_transpose.py"
 python "$HYSOP_DIR/operator/tests/test_derivative.py"
diff --git a/hysop/__init__.py b/hysop/__init__.py
index 3d858751360fa2b672c80e971cf6a117ef995fc6..5002ef3da3eb815276f1d1944d41d969d5fb6537 100644
--- a/hysop/__init__.py
+++ b/hysop/__init__.py
@@ -45,8 +45,8 @@ __TEST_ALL_OPENCL_PLATFORMS__ = get_env('TEST_ALL_OPENCL_PLATFORMS', False)
 __ENABLE_LONG_TESTS__ = get_env('ENABLE_LONG_TESTS', ("OFF" is "ON"))
 
 # OpenCL
-__DEFAULT_PLATFORM_ID__ = get_env('DEFAULT_PLATFORM_ID', 0)
-__DEFAULT_DEVICE_ID__   = get_env('DEFAULT_DEVICE_ID', 0)
+__DEFAULT_PLATFORM_ID__ = int(get_env('DEFAULT_PLATFORM_ID', 0))
+__DEFAULT_DEVICE_ID__   = int(get_env('DEFAULT_DEVICE_ID', 0))
 
 
 if __MPI_ENABLED__:
diff --git a/hysop/__init__.py.in b/hysop/__init__.py.in
index 8037731957abe6e93d8225e8b3f5d1a977e2f486..f63bf48fa96c06638b6b80dfccf9633937ec5b06 100644
--- a/hysop/__init__.py.in
+++ b/hysop/__init__.py.in
@@ -45,8 +45,8 @@ __TEST_ALL_OPENCL_PLATFORMS__ = get_env('TEST_ALL_OPENCL_PLATFORMS', False)
 __ENABLE_LONG_TESTS__ = get_env('ENABLE_LONG_TESTS', ("@ENABLE_LONG_TESTS@" is "ON"))
 
 # OpenCL
-__DEFAULT_PLATFORM_ID__ = get_env('DEFAULT_PLATFORM_ID', @OPENCL_DEFAULT_OPENCL_PLATFORM_ID@)
-__DEFAULT_DEVICE_ID__   = get_env('DEFAULT_DEVICE_ID', @OPENCL_DEFAULT_OPENCL_DEVICE_ID@)
+__DEFAULT_PLATFORM_ID__ = int(get_env('DEFAULT_PLATFORM_ID', @OPENCL_DEFAULT_OPENCL_PLATFORM_ID@))
+__DEFAULT_DEVICE_ID__   = int(get_env('DEFAULT_DEVICE_ID', @OPENCL_DEFAULT_OPENCL_DEVICE_ID@))
 
 if __MPI_ENABLED__:
     from hysop.core.mpi import MPI, main_rank, main_size, \
diff --git a/hysop/core/arrays/tests/test_array.py b/hysop/core/arrays/tests/test_array.py
index 39eaf54d0ee5cc6f0a7b95fc1f21b252b1617487..ef66f3e421f1e539033c48dfa9f95a59922bbe8e 100644
--- a/hysop/core/arrays/tests/test_array.py
+++ b/hysop/core/arrays/tests/test_array.py
@@ -546,14 +546,15 @@ class TestArray(object):
                     tol = atol[0]
                     if not close:
                         close = allclose(r0,r1,relaxed_precision=True,ignore_mask=mask)
-                        tol = 1e-2
+                        tol = 1e-1
                         if close:
                             msg='WARNING: test passed with relaxed precision for {}::{}.'
                             msg=msg.format(backend.__class__.__name__, opname)
                             print msg
                     if not close:
                         msg = '\n{}::{} returned dtypes did match (got {}) '
-                        msg+= 'but failed to match numpy output,\n absolute tolerance was set to {}.'
+                        msg+= 'but failed to match numpy output,'
+                        msg+='\n absolute tolerance was set to {}.'
                         msg=msg.format(backend.__class__.__name__,opname,r1.dtype,tol)
                         print msg
                         if isinstance(r0, np.ndarray) and isinstance(r1, np.ndarray):
diff --git a/hysop/operator/tests/test_directional_advection.py b/hysop/operator/tests/test_directional_advection.py
index 6e5c440c5f61f20080a53f46b9109addbc57d953..f64496d4fa761dca501d854f691a14da2884d268 100644
--- a/hysop/operator/tests/test_directional_advection.py
+++ b/hysop/operator/tests/test_directional_advection.py
@@ -59,8 +59,8 @@ class TestDirectionalAdvectionOperator(object):
         else:
             flt_types = (npw.float,)
             time_integrators = (RK2,)
-            remesh_kernels = (Remesh.L4_2, Remesh.L4_2s,)
-            velocity_cfls = (0.62, 1.89)
+            remesh_kernels = (Remesh.L4_2,)
+            velocity_cfls = (1.89,)
         
         domain = Box(length=(2*npw.pi,)*dim)
         for dtype in flt_types: