diff --git a/app/common/src/main/java/stirling/software/common/util/FileToPdf.java b/app/common/src/main/java/stirling/software/common/util/FileToPdf.java
index 799f91e05..9d208e971 100644
--- a/app/common/src/main/java/stirling/software/common/util/FileToPdf.java
+++ b/app/common/src/main/java/stirling/software/common/util/FileToPdf.java
@@ -124,20 +124,21 @@ public class FileToPdf {
     private static void zipDirectory(Path sourceDir, Path zipFilePath) throws IOException {
         try (ZipOutputStream zos =
                 new ZipOutputStream(new FileOutputStream(zipFilePath.toFile()))) {
-            Files.walk(sourceDir)
-                    .filter(path -> !Files.isDirectory(path))
-                    .forEach(
-                            path -> {
-                                ZipEntry zipEntry =
-                                        new ZipEntry(sourceDir.relativize(path).toString());
-                                try {
-                                    zos.putNextEntry(zipEntry);
-                                    Files.copy(path, zos);
-                                    zos.closeEntry();
-                                } catch (IOException e) {
-                                    throw new UncheckedIOException(e);
-                                }
-                            });
+            try (Stream<Path> walk = Files.walk(sourceDir)) {
+                walk.filter(path -> !Files.isDirectory(path))
+                        .forEach(
+                                path -> {
+                                    ZipEntry zipEntry =
+                                            new ZipEntry(sourceDir.relativize(path).toString());
+                                    try {
+                                        zos.putNextEntry(zipEntry);
+                                        Files.copy(path, zos);
+                                        zos.closeEntry();
+                                    } catch (IOException e) {
+                                        throw new UncheckedIOException(e);
+                                    }
+                                });
+            }
         }
     }
 
diff --git a/app/core/src/main/java/stirling/software/SPDF/controller/api/converters/ConvertImgPDFController.java b/app/core/src/main/java/stirling/software/SPDF/controller/api/converters/ConvertImgPDFController.java
index be2e55df7..09a605156 100644
--- a/app/core/src/main/java/stirling/software/SPDF/controller/api/converters/ConvertImgPDFController.java
+++ b/app/core/src/main/java/stirling/software/SPDF/controller/api/converters/ConvertImgPDFController.java
@@ -9,6 +9,7 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Stream;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
 
@@ -150,10 +151,11 @@ public class ConvertImgPDFController {
                                 .runCommandWithOutputHandling(command);
 
                 // Find all WebP files in the output directory
-                List<Path> webpFiles =
-                        Files.walk(tempOutputDir)
-                                .filter(path -> path.toString().endsWith(".webp"))
-                                .toList();
+                List<Path> webpFiles;
+                try (Stream<Path> walkStream = Files.walk(tempOutputDir)) {
+                    webpFiles =
+                            walkStream.filter(path -> path.toString().endsWith(".webp")).toList();
+                }
 
                 if (webpFiles.isEmpty()) {
                     log.error("No WebP files were created in: {}", tempOutputDir.toString());
diff --git a/app/core/src/main/java/stirling/software/SPDF/controller/api/filters/FilterController.java b/app/core/src/main/java/stirling/software/SPDF/controller/api/filters/FilterController.java
index cf60b3d95..7455ad1de 100644
--- a/app/core/src/main/java/stirling/software/SPDF/controller/api/filters/FilterController.java
+++ b/app/core/src/main/java/stirling/software/SPDF/controller/api/filters/FilterController.java
@@ -48,10 +48,12 @@ public class FilterController {
         String text = request.getText();
         String pageNumber = request.getPageNumbers();
 
-        PDDocument pdfDocument = pdfDocumentFactory.load(inputFile);
-        if (PdfUtils.hasText(pdfDocument, pageNumber, text))
-            return WebResponseUtils.pdfDocToWebResponse(
-                    pdfDocument, Filenames.toSimpleFileName(inputFile.getOriginalFilename()));
+        try (PDDocument pdfDocument = pdfDocumentFactory.load(inputFile)) {
+            if (PdfUtils.hasText(pdfDocument, pageNumber, text)) {
+                return WebResponseUtils.pdfDocToWebResponse(
+                        pdfDocument, Filenames.toSimpleFileName(inputFile.getOriginalFilename()));
+            }
+        }
         return null;
     }
 
diff --git a/app/core/src/main/java/stirling/software/SPDF/controller/api/misc/ExtractImageScansController.java b/app/core/src/main/java/stirling/software/SPDF/controller/api/misc/ExtractImageScansController.java
index ba3bc5f39..bb4490163 100644
--- a/app/core/src/main/java/stirling/software/SPDF/controller/api/misc/ExtractImageScansController.java
+++ b/app/core/src/main/java/stirling/software/SPDF/controller/api/misc/ExtractImageScansController.java
@@ -8,6 +8,7 @@ import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.stream.Stream;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipOutputStream;
 
@@ -142,7 +143,10 @@ public class ExtractImageScansController {
                                 .runCommandWithOutputHandling(command);
 
                 // Read the output photos in temp directory
-                List<Path> tempOutputFiles = Files.list(tempDir).sorted().toList();
+                List<Path> tempOutputFiles;
+                try (Stream<Path> listStream = Files.list(tempDir)) {
+                    tempOutputFiles = listStream.sorted().toList();
+                }
                 for (Path tempOutputFile : tempOutputFiles) {
                     byte[] imageBytes = Files.readAllBytes(tempOutputFile);
                     processedImageBytes.add(imageBytes);
diff --git a/app/core/src/main/java/stirling/software/SPDF/service/SignatureService.java b/app/core/src/main/java/stirling/software/SPDF/service/SignatureService.java
index 1d25f409f..fd27439ed 100644
--- a/app/core/src/main/java/stirling/software/SPDF/service/SignatureService.java
+++ b/app/core/src/main/java/stirling/software/SPDF/service/SignatureService.java
@@ -7,6 +7,7 @@ import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Stream;
 
 import org.springframework.stereotype.Service;
 import org.thymeleaf.util.StringUtils;
@@ -66,10 +67,11 @@ public class SignatureService {
 
     private List<SignatureFile> getSignaturesFromFolder(Path folder, String category)
             throws IOException {
-        return Files.list(folder)
-                .filter(path -> isImageFile(path))
-                .map(path -> new SignatureFile(path.getFileName().toString(), category))
-                .toList();
+        try (Stream<Path> stream = Files.list(folder)) {
+            return stream.filter(this::isImageFile)
+                    .map(path -> new SignatureFile(path.getFileName().toString(), category))
+                    .toList();
+        }
     }
 
     public byte[] getSignatureBytes(String username, String fileName) throws IOException {