diff --git a/java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/BruteForcePrimeChecker.java b/java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/BruteForcePrimeChecker.java
index 68382c26ea..7af8c5d58d 100644
--- a/java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/BruteForcePrimeChecker.java
+++ b/java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/BruteForcePrimeChecker.java
@@ -7,7 +7,7 @@ public class BruteForcePrimeChecker implements PrimeChecker<Integer> {
     @Override
     public boolean isPrime(Integer number) {
 
-        return number > 2 ? IntStream.range(2, number)
+        return number > 1 ? IntStream.range(2, number)
             .noneMatch(n -> (number % n == 0)) : false;
     }
 
diff --git a/java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/OptimisedPrimeChecker.java b/java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/OptimisedPrimeChecker.java
index 3dc372ad22..3019c76eb4 100644
--- a/java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/OptimisedPrimeChecker.java
+++ b/java-numbers-2/src/main/java/com/baeldung/algorithms/primechecker/OptimisedPrimeChecker.java
@@ -6,7 +6,7 @@ public class OptimisedPrimeChecker implements PrimeChecker<Integer> {
 
     @Override
     public boolean isPrime(Integer number) {
-        return number > 2 ? IntStream.rangeClosed(2, (int) Math.sqrt(number))
+        return number > 1 ? IntStream.rangeClosed(2, (int) Math.sqrt(number))
             .noneMatch(n -> (number % n == 0)) : false;
     }
 
diff --git a/java-numbers-2/src/test/java/com/baeldung/algorithms/primechecker/PrimeCheckerUnitTest.java b/java-numbers-2/src/test/java/com/baeldung/algorithms/primechecker/PrimeCheckerUnitTest.java
index 9f8ba8defd..6e425b3051 100644
--- a/java-numbers-2/src/test/java/com/baeldung/algorithms/primechecker/PrimeCheckerUnitTest.java
+++ b/java-numbers-2/src/test/java/com/baeldung/algorithms/primechecker/PrimeCheckerUnitTest.java
@@ -11,22 +11,24 @@ public class PrimeCheckerUnitTest {
 
     @Test
     public void whenCheckIsPrime_thenTrue() {
-        assertTrue(primeChecker.isPrime(13l));
+        assertTrue(primeChecker.isPrime(2L));
+        assertTrue(primeChecker.isPrime(13L));
         assertTrue(primeChecker.isPrime(1009L));
         assertTrue(primeChecker.isPrime(74207281L));
     }
 
     @Test
     public void whenCheckIsPrime_thenFalse() {
-        assertTrue(!primeChecker.isPrime(50L));
-        assertTrue(!primeChecker.isPrime(1001L));
-        assertTrue(!primeChecker.isPrime(74207282L));
+        assertFalse(primeChecker.isPrime(50L));
+        assertFalse(primeChecker.isPrime(1001L));
+        assertFalse(primeChecker.isPrime(74207282L));
     }
 
     private final BruteForcePrimeChecker bfPrimeChecker = new BruteForcePrimeChecker();
 
     @Test
     public void whenBFCheckIsPrime_thenTrue() {
+        assertTrue(bfPrimeChecker.isPrime(2));
         assertTrue(bfPrimeChecker.isPrime(13));
         assertTrue(bfPrimeChecker.isPrime(1009));
     }
@@ -41,6 +43,7 @@ public class PrimeCheckerUnitTest {
 
     @Test
     public void whenOptCheckIsPrime_thenTrue() {
+        assertTrue(optimisedPrimeChecker.isPrime(2));
         assertTrue(optimisedPrimeChecker.isPrime(13));
         assertTrue(optimisedPrimeChecker.isPrime(1009));
     }
@@ -55,6 +58,7 @@ public class PrimeCheckerUnitTest {
 
     @Test
     public void whenPrimesCheckIsPrime_thenTrue() {
+        assertTrue(primesPrimeChecker.isPrime(2));
         assertTrue(primesPrimeChecker.isPrime(13));
         assertTrue(primesPrimeChecker.isPrime(1009));
     }