diff --git a/src/main/java/gq/malwarefight/narumiideobfgui/DeobfuscatorGUIController.java b/src/main/java/gq/malwarefight/narumiideobfgui/DeobfuscatorGUIController.java
index 4e28dc7..5fd8719 100644
--- a/src/main/java/gq/malwarefight/narumiideobfgui/DeobfuscatorGUIController.java
+++ b/src/main/java/gq/malwarefight/narumiideobfgui/DeobfuscatorGUIController.java
@@ -16,13 +16,12 @@
 
 import java.io.File;
 import java.io.FileNotFoundException;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.HashMap;
 
 public class DeobfuscatorGUIController {
 
-    private File inputFile;
-    private File outputFile;
     private final HashMap<CheckBox, Transformer> deobfuscatorHashMap = new HashMap<>();
 
     @FXML
@@ -39,25 +38,31 @@ public class DeobfuscatorGUIController {
     protected void chooseInputFile() {
         FileChooser fileChooser = new FileChooser();
         fileChooser.setInitialDirectory(new File(System.getProperty("user.dir")));
+        fileChooser.getExtensionFilters().addAll(
+                new FileChooser.ExtensionFilter("Jar Files", "*.jar", "*.zip"),
+                new FileChooser.ExtensionFilter("Other Files", "*.*")
+        );
         File input = fileChooser.showOpenDialog(DeobfuscatorGUIApp.stage);
         if (input == null) {
             return;
         }
         inputName.setText(input.getPath());
-        this.inputFile = input;
     }
 
     @FXML
     protected void chooseOutputFile() {
         FileChooser fileChooser = new FileChooser();
         fileChooser.setInitialDirectory(new File(System.getProperty("user.dir")));
+        fileChooser.getExtensionFilters().addAll(
+                new FileChooser.ExtensionFilter("Jar Files", "*.jar", "*.zip"),
+                new FileChooser.ExtensionFilter("Other Files", "*.*")
+        );
         File output = fileChooser.showSaveDialog(DeobfuscatorGUIApp.stage);
         if (output == null) {
             return;
         }
         String path = output.getPath();
         outputName.setText(path);
-        this.outputFile = output;
     }
 
     @FXML
@@ -79,7 +84,7 @@ public void initialize() {
 
     @FXML
     protected void deobfuscate() {
-        if (inputFile == null || outputFile == null){
+        if (inputName.getText() == null || outputName.getText() == null || inputName.getText().isBlank() || outputName.getText().isBlank()){
             result.setText("You need to specify both input and output files!");
             return;
         }
@@ -96,8 +101,8 @@ protected void deobfuscate() {
         usedTransformers.toArray(transformers);
         try {
             Deobfuscator.builder()
-                    .input(inputFile.toPath())
-                    .output(outputFile.toPath())
+                    .input(Path.of(inputName.getText()))
+                    .output(Path.of(outputName.getText()))
                     .transformers(transformers)
                     .classReaderFlags(ClassReader.SKIP_FRAMES)
                     .classWriterFlags(0)
@@ -105,6 +110,7 @@ protected void deobfuscate() {
                     .build()
                     .start();
         } catch (FileNotFoundException e) {
+            result.setText("One or both of the files don't exist");
             return;
         }
         result.setText("Deobfuscation complete");