diff --git a/src/main/java/de/cuioss/tools/io/FileLoaderUtility.java b/src/main/java/de/cuioss/tools/io/FileLoaderUtility.java
index a1271316..b4a493ae 100644
--- a/src/main/java/de/cuioss/tools/io/FileLoaderUtility.java
+++ b/src/main/java/de/cuioss/tools/io/FileLoaderUtility.java
@@ -18,7 +18,6 @@
 import lombok.AccessLevel;
 import lombok.NoArgsConstructor;
 
-import java.io.BufferedInputStream;
 import java.io.IOException;
 import java.io.StringWriter;
 import java.nio.charset.Charset;
@@ -99,7 +98,7 @@ public static Path copyFileToTemp(final FileLoader source, final boolean markDel
         final Path target = PathTraversalSecurity.createSecureTempFile(namePart, null != suffix ? "." + suffix : null);
 
         try (final var inputStream = source.inputStream()) {
-            Files.copy(new BufferedInputStream(inputStream), target, StandardCopyOption.REPLACE_EXISTING);
+            Files.copy(inputStream, target, StandardCopyOption.REPLACE_EXISTING);
         }
         if (markDeleteOnExit) {
             target.toFile().deleteOnExit();
diff --git a/src/test/java/de/cuioss/tools/collect/CollectionLiteralsTest.java b/src/test/java/de/cuioss/tools/collect/CollectionLiteralsTest.java
index 7202a5bc..e19f076d 100644
--- a/src/test/java/de/cuioss/tools/collect/CollectionLiteralsTest.java
+++ b/src/test/java/de/cuioss/tools/collect/CollectionLiteralsTest.java
@@ -284,7 +284,7 @@ void shouldCopySourceMapForImmutableMap() {
         @DisplayName("Should handle stream to immutable map conversion")
         void shouldHandleStreamToImmutableMap() {
             final Map<String, String> result = immutableMap(
-                    immutableMap("1", "1-1", "2", "").entrySet().stream().filter(entry -> !"".equals(entry.getValue())));
+                    immutableMap("1", "1-1", "2", "").entrySet().stream().filter(entry -> !entry.getValue().isEmpty()));
             assertEquals(1, result.size());
             assertTrue(result.containsKey("1"));
         }
diff --git a/src/test/java/de/cuioss/tools/io/FileSystemLoaderTest.java b/src/test/java/de/cuioss/tools/io/FileSystemLoaderTest.java
index 54fc33f1..d63e7073 100644
--- a/src/test/java/de/cuioss/tools/io/FileSystemLoaderTest.java
+++ b/src/test/java/de/cuioss/tools/io/FileSystemLoaderTest.java
@@ -16,8 +16,10 @@
 package de.cuioss.tools.io;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
 
 import java.io.File;
+import java.nio.file.Files;
 import java.nio.file.Path;
 
 import static org.junit.jupiter.api.Assertions.*;
@@ -134,10 +136,9 @@ void shouldFailToLoadNotExistingFile() {
     }
 
     @Test
-    void shouldHandleOutputStreamForWritableFile() throws Exception {
-        // Create a temporary file for testing
-        File tempFile = File.createTempFile("test", ".txt");
-        tempFile.deleteOnExit();
+    void shouldHandleOutputStreamForWritableFile(@TempDir Path tempDir) throws Exception {
+        // Create a temporary file inside the JUnit-managed temp directory (auto-cleaned)
+        File tempFile = Files.createFile(tempDir.resolve("test.txt")).toFile();
 
         var loader = new FileSystemLoader(tempFile.getAbsolutePath());
         assertTrue(loader.isWritable());
diff --git a/src/test/java/de/cuioss/tools/support/TestDataGenerator.java b/src/test/java/de/cuioss/tools/support/TestDataGenerator.java
index 828f0ea3..b8b7cc5c 100644
--- a/src/test/java/de/cuioss/tools/support/TestDataGenerator.java
+++ b/src/test/java/de/cuioss/tools/support/TestDataGenerator.java
@@ -54,7 +54,7 @@ public Class<byte[]> getType() {
     }
 
     private static void generateTestData(final OutputStream out, final long size) throws IOException {
-        for (var i = 0; i < size; i++) {
+        for (long i = 0; i < size; i++) {
             // nice varied byte pattern compatible with Readers and Writers
             out.write((byte) (i % 127 + 1));
         }