diff --git a/src/qiboml/operations/expectation.py b/src/qiboml/operations/expectation.py
index 228e910..cd84f16 100644
--- a/src/qiboml/operations/expectation.py
+++ b/src/qiboml/operations/expectation.py
@@ -57,7 +57,7 @@ def expectation(
         nshots=nshots,
         backend=backend,
         differentiation_rule=differentiation_rule,
-        exec_backend=exec_backend,
+        backend=exec_backend,
     )
 
     if differentiation_rule is not None: