diff --git a/src/main/java/ru/lionarius/IntegralCalculator.java b/src/main/java/ru/lionarius/IntegralCalculator.java
index b1e7679..342c17e 100644
--- a/src/main/java/ru/lionarius/IntegralCalculator.java
+++ b/src/main/java/ru/lionarius/IntegralCalculator.java
@@ -122,15 +122,12 @@ public class IntegralCalculator {
             currentStart = end;
 
             futures.add(executor.submit(() -> {
-                var prevSteps = 0;
-                var steps = 0;
                 var partitionSum = 0.0;
                 for (var j = start; j < end; j++) {
                     partitionSum += function.apply(lowerBound + h * j);
-                    steps++;
 
                     var progress = total.incrementAndGet();
-                    progressCallback.accept(progress, n);
+                    this.callProgressCallback(progress, n);
                 }
 
                 return partitionSum;