diff --git a/src/ansys/fluent/core/filereader/case_file.py b/src/ansys/fluent/core/filereader/case_file.py
index 2842a2f3235..cd0ad4a4e5d 100644
--- a/src/ansys/fluent/core/filereader/case_file.py
+++ b/src/ansys/fluent/core/filereader/case_file.py
@@ -346,7 +346,7 @@ def get_connectivity(self, surface_id) -> np.array:
         key = np.unique(key)
         value = np.arange(0, len(key))
         replace = np.array([key, value])
-        mask = np.in1d(nodes, key)
+        mask = np.isin(nodes, key)
         nodes[mask] = replace[1, np.searchsorted(replace[0, :], nodes[mask])]
         obj = np.cumsum(nnodes)
         obj = np.insert(obj, 0, 0)