diff --git a/hysop/core/graph/computational_node_frontend.py b/hysop/core/graph/computational_node_frontend.py
index 77b14e2d7344eae4a725539ef6ef53f079c3a9e1..ab75850b0a4d96dbef14c94f604bf56e384cd85a 100644
--- a/hysop/core/graph/computational_node_frontend.py
+++ b/hysop/core/graph/computational_node_frontend.py
@@ -1,3 +1,4 @@
+import inspect
 from hysop.constants import Implementation, Backend, implementation_to_backend
 from hysop.tools.decorators  import debug
 from hysop.tools.types import check_instance, first_not_None
@@ -87,6 +88,12 @@ class ComputationalGraphNodeFrontend(ComputationalGraphNodeGenerator):
             msg+= 'available implementations are:\n {}'
             msg=msg.format(implementation, '\n '.join(simplementations))
             raise ValueError(msg)
+        elif (self.implementations()[implementation] is None):
+            msg = 'Specified implementation \'{}\' is registered as an available implementation for operator \'{}\', '
+            msg+= 'but no underlying implementation was found. This may be due to missing dependency or a catched '
+            msg+= 'import error in file file://{}.'
+            msg=msg.format(implementation, self.__class__.__name__, inspect.getfile(self.__class__)[:-1])
+            raise ValueError(msg)
 
         self.implementation = implementation
         self.backend   = implementation_to_backend(implementation)
@@ -96,6 +103,7 @@ class ComputationalGraphNodeFrontend(ComputationalGraphNodeGenerator):
         self._input_fields_to_dump  = []
         self._output_fields_to_dump = []
 
+
     @debug
     def _generate(self):
         try: