diff --git a/core/types.rs b/core/types.rs
index bccd647c0..a5ddaa906 100644
--- a/core/types.rs
+++ b/core/types.rs
@@ -401,14 +401,6 @@ pub struct ExternalAggState {
     pub argc: usize,
     pub step_fn: StepFunction,
     pub finalize_fn: FinalizeFunction,
-    pub finalized_value: Option<Value>,
-}
-
-impl ExternalAggState {
-    pub fn cache_final_value(&mut self, value: Value) -> &Value {
-        self.finalized_value = Some(value);
-        self.finalized_value.as_ref().unwrap()
-    }
 }
 
 /// Please use Display trait for all limbo output so we have single origin of truth
@@ -634,14 +626,13 @@ pub enum AggContext {
 }
 
 impl AggContext {
-    pub fn compute_external(&mut self) -> Result<()> {
+    pub fn compute_external(&self) -> Result<Value> {
         if let Self::External(ext_state) = self {
-            if ext_state.finalized_value.is_none() {
-                let final_value = unsafe { (ext_state.finalize_fn)(ext_state.state) };
-                ext_state.cache_final_value(Value::from_ffi(final_value)?);
-            }
+            let final_value = unsafe { (ext_state.finalize_fn)(ext_state.state) };
+            Value::from_ffi(final_value)
+        } else {
+            panic!("AggContext::compute_external() expected External, found {self:?}");
         }
-        Ok(())
     }
 }
 
diff --git a/core/vdbe/execute.rs b/core/vdbe/execute.rs
index 280caa520..41a3baed3 100644
--- a/core/vdbe/execute.rs
+++ b/core/vdbe/execute.rs
@@ -3468,7 +3468,6 @@ pub fn op_agg_step(
                     argc: *argc,
                     step_fn: *step,
                     finalize_fn: *finalize,
-                    finalized_value: None,
                 })),
                 _ => unreachable!("scalar function called in aggregate context"),
             },
@@ -3736,17 +3735,17 @@ pub fn op_agg_final(
     mv_store: Option<&Arc<MvStore>>,
 ) -> Result<InsnFunctionStepResult> {
     load_insn!(AggFinal { register, func }, insn);
-    match state.registers[*register].borrow_mut() {
+    match &state.registers[*register] {
         Register::Aggregate(agg) => match func {
             AggFunc::Avg => {
-                let AggContext::Avg(acc, count) = agg.borrow_mut() else {
+                let AggContext::Avg(acc, count) = agg else {
                     unreachable!();
                 };
-                *acc /= count.clone();
-                state.registers[*register] = Register::Value(acc.clone());
+                let acc = acc.clone() / count.clone();
+                state.registers[*register] = Register::Value(acc);
             }
             AggFunc::Sum => {
-                let AggContext::Sum(acc, sum_state) = agg.borrow_mut() else {
+                let AggContext::Sum(acc, sum_state) = agg else {
                     unreachable!();
                 };
                 let value = match acc {
@@ -3762,7 +3761,7 @@ pub fn op_agg_final(
                 state.registers[*register] = Register::Value(value);
             }
             AggFunc::Total => {
-                let AggContext::Sum(acc, _) = agg.borrow_mut() else {
+                let AggContext::Sum(acc, _) = agg else {
                     unreachable!();
                 };
                 let value = match acc {
@@ -3774,13 +3773,13 @@ pub fn op_agg_final(
                 state.registers[*register] = Register::Value(value);
             }
             AggFunc::Count | AggFunc::Count0 => {
-                let AggContext::Count(count) = agg.borrow_mut() else {
+                let AggContext::Count(count) = agg else {
                     unreachable!();
                 };
                 state.registers[*register] = Register::Value(count.clone());
             }
             AggFunc::Max => {
-                let AggContext::Max(acc) = agg.borrow_mut() else {
+                let AggContext::Max(acc) = agg else {
                     unreachable!();
                 };
                 match acc {
@@ -3789,7 +3788,7 @@ pub fn op_agg_final(
                 }
             }
             AggFunc::Min => {
-                let AggContext::Min(acc) = agg.borrow_mut() else {
+                let AggContext::Min(acc) = agg else {
                     unreachable!();
                 };
                 match acc {
@@ -3798,14 +3797,14 @@ pub fn op_agg_final(
                 }
             }
             AggFunc::GroupConcat | AggFunc::StringAgg => {
-                let AggContext::GroupConcat(acc) = agg.borrow_mut() else {
+                let AggContext::GroupConcat(acc) = agg else {
                     unreachable!();
                 };
                 state.registers[*register] = Register::Value(acc.clone());
             }
             #[cfg(feature = "json")]
             AggFunc::JsonGroupObject => {
-                let AggContext::GroupConcat(acc) = agg.borrow_mut() else {
+                let AggContext::GroupConcat(acc) = agg else {
                     unreachable!();
                 };
                 let data = acc.to_blob().expect("Should be blob");
@@ -3813,7 +3812,7 @@ pub fn op_agg_final(
             }
             #[cfg(feature = "json")]
             AggFunc::JsonbGroupObject => {
-                let AggContext::GroupConcat(acc) = agg.borrow_mut() else {
+                let AggContext::GroupConcat(acc) = agg else {
                     unreachable!();
                 };
                 let data = acc.to_blob().expect("Should be blob");
@@ -3821,7 +3820,7 @@ pub fn op_agg_final(
             }
             #[cfg(feature = "json")]
             AggFunc::JsonGroupArray => {
-                let AggContext::GroupConcat(acc) = agg.borrow_mut() else {
+                let AggContext::GroupConcat(acc) = agg else {
                     unreachable!();
                 };
                 let data = acc.to_blob().expect("Should be blob");
@@ -3829,21 +3828,18 @@ pub fn op_agg_final(
             }
             #[cfg(feature = "json")]
             AggFunc::JsonbGroupArray => {
-                let AggContext::GroupConcat(acc) = agg.borrow_mut() else {
+                let AggContext::GroupConcat(acc) = agg else {
                     unreachable!();
                 };
                 let data = acc.to_blob().expect("Should be blob");
                 state.registers[*register] = Register::Value(json_from_raw_bytes_agg(data, true)?);
             }
             AggFunc::External(_) => {
-                agg.compute_external()?;
                 let AggContext::External(agg_state) = agg else {
                     unreachable!();
                 };
-                match &agg_state.finalized_value {
-                    Some(value) => state.registers[*register] = Register::Value(value.clone()),
-                    None => state.registers[*register] = Register::Value(Value::Null),
-                }
+                let value = agg.compute_external()?;
+                state.registers[*register] = Register::Value(value)
             }
         },
         Register::Value(Value::Null) => {