diff --git a/core-java-modules/core-java-os/src/test/java/com/baeldung/grep/GrepWithUnix4JIntegrationTest.java b/core-java-modules/core-java-os/src/test/java/com/baeldung/grep/GrepWithUnix4JIntegrationTest.java
index 3ea7acf620..5c9da0cc9e 100644
--- a/core-java-modules/core-java-os/src/test/java/com/baeldung/grep/GrepWithUnix4JIntegrationTest.java
+++ b/core-java-modules/core-java-os/src/test/java/com/baeldung/grep/GrepWithUnix4JIntegrationTest.java
@@ -25,9 +25,9 @@ public class GrepWithUnix4JIntegrationTest {
 
     @Test
     public void whenGrepWithSimpleString_thenCorrect() {
-        int expectedLineCount = 4;
+        int expectedLineCount = 5;
 
-        // grep "NINETEEN" dictionary.txt
+        // grep "NINETEEN" dictionary.in
         List<Line> lines = Unix4j.grep("NINETEEN", fileToGrep).toLineList();
 
         assertEquals(expectedLineCount, lines.size());
@@ -35,9 +35,9 @@ public class GrepWithUnix4JIntegrationTest {
 
     @Test
     public void whenInverseGrepWithSimpleString_thenCorrect() {
-        int expectedLineCount = 178687;
+        int expectedLineCount = 8;
 
-        // grep -v "NINETEEN" dictionary.txt
+        // grep -v "NINETEEN" dictionary.in
         List<Line> lines = grep(Options.v, "NINETEEN", fileToGrep).toLineList();
 
         assertEquals(expectedLineCount, lines.size());
@@ -45,9 +45,9 @@ public class GrepWithUnix4JIntegrationTest {
 
     @Test
     public void whenGrepWithRegex_thenCorrect() {
-        int expectedLineCount = 151;
+        int expectedLineCount = 5;
 
-        // grep -c ".*?NINE.*?" dictionary.txt
+        // grep -c ".*?NINE.*?" dictionary.in
         String patternCount = grep(Options.c, ".*?NINE.*?", fileToGrep).cut(fields, ":", 1).toStringResult();
 
         assertEquals(expectedLineCount, Integer.parseInt(patternCount));
diff --git a/core-java-modules/core-java-os/src/test/resources/dictionary.in b/core-java-modules/core-java-os/src/test/resources/dictionary.in
new file mode 100644
index 0000000000..9e6c74ecdb
--- /dev/null
+++ b/core-java-modules/core-java-os/src/test/resources/dictionary.in
@@ -0,0 +1,13 @@
+EIGHTTEEN
+EIGHTTEENS
+EIGHTTEENTH
+EIGHTTEENTHS
+NINETEEN
+NINETEENS
+NINETEENTH
+NINETEENTHS
+TWENTY
+TWENTHIES
+TWENTHIETH
+TWENTHIETHS
+TWENTYNINETEEN
\ No newline at end of file