diff --git a/src/pystencils/astnodes.py b/src/pystencils/astnodes.py
index a54d350bc936258c6a4ba327fc1818b1d02597c5..c8928a218afeecc1c914a55696826ed7d055cf62 100644
--- a/src/pystencils/astnodes.py
+++ b/src/pystencils/astnodes.py
@@ -9,8 +9,8 @@ from pystencils.assignment import Assignment
 from pystencils.enums import Target, Backend
 from pystencils.field import Field
 from pystencils.sympyextensions import fast_subs
-from pystencils.typing import (CFunction, create_type, get_next_parent_of_type,
-                               FieldPointerSymbol, FieldShapeSymbol, FieldStrideSymbol, TypedSymbol)
+from pystencils.typing import (create_type, get_next_parent_of_type,
+                               FieldPointerSymbol, FieldShapeSymbol, FieldStrideSymbol, TypedSymbol, CFunction)
 
 NodeOrExpr = Union['Node', sp.Expr]
 
@@ -272,7 +272,7 @@ class KernelFunction(Node):
             parameters += [self.Parameter(s, []) for s in self.indexing.symbolic_parameters()]
         # Exclude paramters of type CFunction. These parameters will result in a C function call that will be handled
         # by including a respective header file in the compute kernel. Hence, it is not a free parameter.
-        # parameters = [p for p in parameters if not isinstance(p.symbol, CFunction)]
+        parameters = [p for p in parameters if not isinstance(p.symbol, CFunction)]
         parameters.sort(key=lambda p: p.symbol.name)
         return parameters