diff --git a/core-java/src/main/java/com/baeldung/stackoverflowerror/RecursionWithCorrectTerminationCondition.java b/core-java/src/main/java/com/baeldung/stackoverflowerror/RecursionWithCorrectTerminationCondition.java
index 0c0c392532..16d771f389 100644
--- a/core-java/src/main/java/com/baeldung/stackoverflowerror/RecursionWithCorrectTerminationCondition.java
+++ b/core-java/src/main/java/com/baeldung/stackoverflowerror/RecursionWithCorrectTerminationCondition.java
@@ -1,7 +1,7 @@
 package com.baeldung.stackoverflowerror;
 
 public class RecursionWithCorrectTerminationCondition {
-    public static int calculateFactorial(final int number) {
+    public int calculateFactorial(final int number) {
         return number <= 1 ? 1 : number * calculateFactorial(number - 1);
     }
 }
diff --git a/core-java/src/test/java/com/baeldung/stackoverflowerror/InfiniteRecursionWithTerminationConditionManualTest.java b/core-java/src/test/java/com/baeldung/stackoverflowerror/InfiniteRecursionWithTerminationConditionManualTest.java
index 25ef504206..996d0e9017 100644
--- a/core-java/src/test/java/com/baeldung/stackoverflowerror/InfiniteRecursionWithTerminationConditionManualTest.java
+++ b/core-java/src/test/java/com/baeldung/stackoverflowerror/InfiniteRecursionWithTerminationConditionManualTest.java
@@ -6,7 +6,7 @@ import org.junit.Test;
 
 public class InfiniteRecursionWithTerminationConditionManualTest {
     @Test
-    public void givenPositiveIntNoOne_whenCalcFact_thenThrowsException() {
+    public void givenPositiveIntNoOne_whenCalcFact_thenCorrectlyCalc() {
         int numToCalcFactorial = 1;
         InfiniteRecursionWithTerminationCondition irtc = new InfiniteRecursionWithTerminationCondition();
 
@@ -14,7 +14,7 @@ public class InfiniteRecursionWithTerminationConditionManualTest {
     }
 
     @Test
-    public void givenPositiveIntGtOne_whenCalcFact_thenThrowsException() {
+    public void givenPositiveIntGtOne_whenCalcFact_thenCorrectlyCalc() {
         int numToCalcFactorial = 5;
         InfiniteRecursionWithTerminationCondition irtc = new InfiniteRecursionWithTerminationCondition();
 
diff --git a/core-java/src/test/java/com/baeldung/stackoverflowerror/RecursionWithCorrectTerminationConditionManualTest.java b/core-java/src/test/java/com/baeldung/stackoverflowerror/RecursionWithCorrectTerminationConditionManualTest.java
new file mode 100644
index 0000000000..a4269aef56
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/stackoverflowerror/RecursionWithCorrectTerminationConditionManualTest.java
@@ -0,0 +1,15 @@
+package com.baeldung.stackoverflowerror;
+
+import static junit.framework.TestCase.assertEquals;
+
+import org.junit.Test;
+
+public class RecursionWithCorrectTerminationConditionManualTest {
+    @Test
+    public void givenNegativeInt_whenCalcFact_thenCorrectlyCalc() {
+        int numToCalcFactorial = -1;
+        RecursionWithCorrectTerminationCondition rctc = new RecursionWithCorrectTerminationCondition();
+
+        assertEquals(1, rctc.calculateFactorial(numToCalcFactorial));
+    }
+}