diff --git a/app/src/main/java/sudoku/constraint/BlockConstraint.java b/app/src/main/java/sudoku/constraint/BlockConstraint.java
index a0fe7c5..c6adec3 100644
--- a/app/src/main/java/sudoku/constraint/BlockConstraint.java
+++ b/app/src/main/java/sudoku/constraint/BlockConstraint.java
@@ -1,7 +1,6 @@
 package sudoku.constraint;
 
 import sudoku.Block;
-import sudoku.Cell;
 import sudoku.MutableCell;
 import sudoku.Sudoku;
 
diff --git a/app/src/main/java/sudoku/io/SudokuSerializer.java b/app/src/main/java/sudoku/io/SudokuSerializer.java
index 0bb7ca5..b0ab311 100644
--- a/app/src/main/java/sudoku/io/SudokuSerializer.java
+++ b/app/src/main/java/sudoku/io/SudokuSerializer.java
@@ -6,9 +6,6 @@ import java.util.List;
 import org.json.JSONArray;
 import org.json.JSONObject;
 
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.ObjectMapper;
-
 import sudoku.Block;
 import sudoku.Cell;
 import sudoku.ImmutableCell;