diff --git a/src/protocol/eval.rs b/src/protocol/eval.rs
index 4e77eec893d793d355ee1b192726e82ebbbe8577..b89a1a442a3ae9963dfdf345b2fcb0ef887a9a5b 100644
--- a/src/protocol/eval.rs
+++ b/src/protocol/eval.rs
@@ -113,7 +113,7 @@ impl Value {
                     // It is inconsistent to update with a negative value
                     return None;
                 }
-                if let Some(slot) = payload.as_mut_slice().get_mut(the_index) {
+                if let Some(slot) = payload.as_mut_vec().get_mut(the_index) {
                     *slot = (*b).try_into().unwrap();
                     Some(value.clone())
                 } else {
@@ -126,7 +126,7 @@ impl Value {
                     // It is inconsistent to update with a negative value or a too large value
                     return None;
                 }
-                if let Some(slot) = payload.as_mut_slice().get_mut(the_index) {
+                if let Some(slot) = payload.as_mut_vec().get_mut(the_index) {
                     *slot = (*b).try_into().unwrap();
                     Some(value.clone())
                 } else {