diff --git a/executor/src/witgen/data_structures/finalizable_data.rs b/executor/src/witgen/data_structures/finalizable_data.rs
index affbb779f..b119a5db1 100644
--- a/executor/src/witgen/data_structures/finalizable_data.rs
+++ b/executor/src/witgen/data_structures/finalizable_data.rs
@@ -95,17 +95,17 @@ impl<T: FieldElement> CompactData<T> {
 
     pub fn set(&mut self, row: usize, new_row: Row<T>) {
         let idx = row * self.column_count;
-        for (i, col_id) in (self.first_column_id..(self.first_column_id + self.column_count as u64))
-            .enumerate()
+        for (i, col_id) in
+            (self.first_column_id..(self.first_column_id + self.column_count as u64)).enumerate()
         {
             if let Some(v) = new_row.value(&PolyID {
                 id: col_id,
                 ptype: PolynomialType::Committed,
             }) {
                 self.data[idx + i] = v;
-                self.known_cells.set(row, col_id, true);
+                self.known_cells.set(row, i as u64, true);
             } else {
-                self.known_cells.set(row, col_id, false);
+                self.known_cells.set(row, i as u64, false);
             }
         }
     }
diff --git a/executor/src/witgen/jit/block_machine_processor.rs b/executor/src/witgen/jit/block_machine_processor.rs
index 3dd52c0b2..059ea0fe8 100644
--- a/executor/src/witgen/jit/block_machine_processor.rs
+++ b/executor/src/witgen/jit/block_machine_processor.rs
@@ -64,6 +64,17 @@ impl<'a, T: FieldElement> BlockMachineProcessor<'a, T> {
         // In the latch row, set the RHS selector to 1.
         witgen.assign_constant(&connection_rhs.selector, self.latch_row as i32, T::one());
 
+        // Set all other selectors to 0 in the latch row.
+        for other_connection in self.machine_parts.connections.values() {
+            if other_connection.right.selector != connection_rhs.selector {
+                witgen.assign_constant(
+                    &other_connection.right.selector,
+                    self.latch_row as i32,
+                    T::zero(),
+                );
+            }
+        }
+
         // For each argument, connect the expression on the RHS with the formal parameter.
         for (index, expr) in connection_rhs.expressions.iter().enumerate() {
             witgen.assign_variable(expr, self.latch_row as i32, Variable::Param(index));