diff --git a/src/main/java/cz/jzitnik/game/Block.java b/src/main/java/cz/jzitnik/game/Block.java
index 347b76d..2295a7c 100644
--- a/src/main/java/cz/jzitnik/game/Block.java
+++ b/src/main/java/cz/jzitnik/game/Block.java
@@ -48,13 +48,13 @@ public class Block {
         this.spriteState = Optional.of(spriteState);
     }
 
-    public int calculateHardness(Inventory inventory) {
-        int holdingDecrease = 0;
+    public double calculateHardness(Inventory inventory) {
+        double holdingDecrease = 0;
         if (inventory.getItemInHand().isPresent() && tool.isPresent() && inventory.getItemInHand().get().getType().equals(tool.get())) {
             holdingDecrease = inventory.getItemInHand().get().getMiningDecrease();
         }
 
-        int decrease = hardness - holdingDecrease;
+        double decrease = hardness - holdingDecrease;
 
         if (decrease < 0) {
             decrease = 0;
diff --git a/src/main/java/cz/jzitnik/game/Game.java b/src/main/java/cz/jzitnik/game/Game.java
index f942ef6..70367f1 100644
--- a/src/main/java/cz/jzitnik/game/Game.java
+++ b/src/main/java/cz/jzitnik/game/Game.java
@@ -118,13 +118,13 @@ public class Game {
         world[y][x].add(breakingBlock);
         screenRenderer.render(this);
 
-        int hardness = world[y][x].stream().filter(block -> !block.isGhost()).toList().get(0).calculateHardness(inventory);
+        double hardness = world[y][x].stream().filter(block -> !block.isGhost()).toList().get(0).calculateHardness(inventory);
 
         this.mining = true;
 
         new Thread(() -> {
             try {
-                Thread.sleep(hardness * 166L);
+                Thread.sleep((long) (hardness * 166));
             } catch (InterruptedException e) {
                 throw new RuntimeException(e);
             }
@@ -132,7 +132,7 @@ public class Game {
             screenRenderer.render(this);
 
             try {
-                Thread.sleep(hardness * 166L);
+                Thread.sleep((long) (hardness * 166));
             } catch (InterruptedException e) {
                 throw new RuntimeException(e);
             }
@@ -140,7 +140,7 @@ public class Game {
             screenRenderer.render(this);
 
             try {
-                Thread.sleep(hardness * 166L);
+                Thread.sleep((long) (hardness * 166));
             } catch (InterruptedException e) {
                 throw new RuntimeException(e);
             }