diff --git a/src/sudoku_solver.rs b/src/sudoku_solver.rs
index adc56ca..8cafbec 100644
--- a/src/sudoku_solver.rs
+++ b/src/sudoku_solver.rs
@@ -20,18 +20,27 @@ impl SudokuSolver {
     fn populate_possible_values(&mut self) {
         for open_field in &self.playfield.open_fields {
             let row_index = open_field / self.playfield.size;
-            let row = &mut self.playfield.fields[row_index];
+            let row = &self.playfield.fields[row_index];
+
+            let possible_values_row = possible_values_from_vec(row, self.playfield.size as u32);
+
             let col_index = open_field % self.playfield.size;
+            let col = self.playfield.get_column(col_index);
+            let possible_values_col = possible_values_from_vec(&col, self.playfield.size as u32);
 
-            let possible_values = possible_values_from_row(row, self.playfield.size as u32);
+            let possible_values = possible_values_row
+                .symmetric_difference(&possible_values_col)
+                .map(|v| *v)
+                .collect();
 
+            let row = &mut self.playfield.fields[row_index];
             let field = &mut row[col_index];
             field.possible_values = possible_values;
         }
     }
 }
 
-fn possible_values_from_row(row: &Vec<Field>, max_value: u32) -> Vec<u32> {
+fn possible_values_from_vec(row: &Vec<Field>, max_value: u32) -> HashSet<u32> {
     let possible_values: HashSet<u32> = (1..max_value + 1).collect();
 
     let populated_values: HashSet<u32> = row
@@ -94,7 +103,7 @@ mod tests {
             assert!(field_4_values.iter().all(|i| expected_4.contains(i)));
         }
     }
-    mod possible_values_from_row {
+    mod possible_values_from_vec {
         use super::super::*;
         use super::*;
 
@@ -105,9 +114,9 @@ mod tests {
             let expected_row_2 = vec![1, 2];
             let expected_row_3 = vec![1, 2, 3];
 
-            let possible_values_row_1 = possible_values_from_row(&playfield.fields[0], 3);
-            let possible_values_row_2 = possible_values_from_row(&playfield.fields[1], 3);
-            let possible_values_row_3 = possible_values_from_row(&playfield.fields[2], 3);
+            let possible_values_row_1 = possible_values_from_vec(&playfield.fields[0], 3);
+            let possible_values_row_2 = possible_values_from_vec(&playfield.fields[1], 3);
+            let possible_values_row_3 = possible_values_from_vec(&playfield.fields[2], 3);
 
             assert_eq!(possible_values_row_1, expected_row_1);
             assert!(possible_values_row_2