diff --git a/core-java/src/main/java/com/baeldung/file/FileOutputStreamTest.java b/core-java/src/test/java/com/baeldung/file/FileOutputStreamTest.java
similarity index 100%
rename from core-java/src/main/java/com/baeldung/file/FileOutputStreamTest.java
rename to core-java/src/test/java/com/baeldung/file/FileOutputStreamTest.java
diff --git a/core-java/src/main/java/com/baeldung/file/FileUtilsTest.java b/core-java/src/test/java/com/baeldung/file/FileUtilsTest.java
similarity index 100%
rename from core-java/src/main/java/com/baeldung/file/FileUtilsTest.java
rename to core-java/src/test/java/com/baeldung/file/FileUtilsTest.java
diff --git a/core-java/src/main/java/com/baeldung/file/FileWriterTest.java b/core-java/src/test/java/com/baeldung/file/FileWriterTest.java
similarity index 100%
rename from core-java/src/main/java/com/baeldung/file/FileWriterTest.java
rename to core-java/src/test/java/com/baeldung/file/FileWriterTest.java
diff --git a/core-java/src/main/java/com/baeldung/file/FilesTest.java b/core-java/src/test/java/com/baeldung/file/FilesTest.java
similarity index 100%
rename from core-java/src/main/java/com/baeldung/file/FilesTest.java
rename to core-java/src/test/java/com/baeldung/file/FilesTest.java
diff --git a/core-java/src/main/java/com/baeldung/file/GuavaTest.java b/core-java/src/test/java/com/baeldung/file/GuavaTest.java
similarity index 100%
rename from core-java/src/main/java/com/baeldung/file/GuavaTest.java
rename to core-java/src/test/java/com/baeldung/file/GuavaTest.java