diff --git a/lbmpy/phasefield/nphase_nestler.py b/lbmpy/phasefield/nphase_nestler.py
index 2347a2c1b4e0a0296088685b08b3a5a2a9292c38..1437148d2a1fe1911b4c101b0db1d13024b356e5 100644
--- a/lbmpy/phasefield/nphase_nestler.py
+++ b/lbmpy/phasefield/nphase_nestler.py
@@ -1,12 +1,13 @@
 try:
-   import pyximport
-   pyximport.install(language_level=3)
-   from lbmpy.phasefield.simplex_projection import simplex_projection_2d  # NOQA
-except:
+    import pyximport
+
+    pyximport.install(language_level=3)
+    from lbmpy.phasefield.simplex_projection import simplex_projection_2d  # NOQA
+except ImportError:
     try:
         from lbmpy.phasefield.simplex_projection import simplex_projection_2d  # NOQA
-    except:
-        raise ImportError("neither pyximport nor binary module available")
+    except ImportError:
+        raise ImportError("neither pyximport nor binary module simplex_projection_2d available.")
 
 import sympy as sp