diff --git a/app/src/main/java/sudoku/solver/MixedSolver.java b/app/src/main/java/sudoku/solver/MixedSolver.java
index 1084583..5166255 100644
--- a/app/src/main/java/sudoku/solver/MixedSolver.java
+++ b/app/src/main/java/sudoku/solver/MixedSolver.java
@@ -45,6 +45,9 @@ public class MixedSolver implements Solver {
             throw new CancellationException("User wants to stop the solver");
         }
 
+        if (doku.isSolved())
+            return true;
+
         int symbolCount = doku.getSubGrid(0).getSize();
 
         // on remplit les cases par déduction
@@ -56,12 +59,12 @@ public class MixedSolver implements Solver {
             if (possibleSymbols.size() == 1) {
                 cell.setSymbolIndex(possibleSymbols.getFirst());
                 addStep(cell, steps);
+                if (solve(doku, steps))
+                    return true;
+                cell.setSymbolIndex(Cell.NOSYMBOL);
             }
         }
 
-        if (doku.isSolved())
-            return true;
-
         // on ne peut plus remplir de cases, on tente de backtrack
         for (int maxPossibilities = 2; maxPossibilities <= symbolCount; maxPossibilities++) {
             List<Cell> backtrackCells = new ArrayList<>();
@@ -81,15 +84,12 @@ public class MixedSolver implements Solver {
 
                 // on tente de placer chacun des symboles
                 for (int symbol : possibilities) {
-                    var state = doku.getStateManager().pushState();
                     backtrackCell.setSymbolIndex(symbol);
                     if (solve(doku, steps)) {
-                        // doku.getStateManager().forgetState();
                         return true;
                     }
-                    doku.getStateManager().popState();
-                    doku.getStateManager().restoreState(state);
                 }
+                backtrackCell.setSymbolIndex(Cell.NOSYMBOL);
             }
         }
         return doku.isSolved();