diff --git a/src/main/java/click/kamil/springstatemachineexporter/ast/Main.java b/src/main/java/click/kamil/springstatemachineexporter/ast/Main.java
index a29dcf7..98e1ca3 100644
--- a/src/main/java/click/kamil/springstatemachineexporter/ast/Main.java
+++ b/src/main/java/click/kamil/springstatemachineexporter/ast/Main.java
@@ -29,6 +29,7 @@ public class Main {
     private static final List<String> TARGET_ANNOTATIONS = List.of("EnableStateMachineFactory", "EnableStateMachine");
 
     public static void main(String[] args) throws IOException {
+        AstFileFinder finder = new AstFileFinder();
         List<Path> javaFiles = FileUtils.findFilesWithExtension(Paths.get(START_DIR), EXTENSION);
 
         // List of output handlers
@@ -40,7 +41,6 @@ public class Main {
 
         for (Path javaFile : javaFiles) {
             String source = Files.readString(javaFile);
-            AstFileFinder finder = new AstFileFinder(source);
 
             if (finder.hasClassWithAnnotation(source, TARGET_ANNOTATIONS)) {
                 System.out.println("Found annotation in: " + javaFile.toAbsolutePath());
diff --git a/src/main/java/click/kamil/springstatemachineexporter/ast/in/AstFileFinder.java b/src/main/java/click/kamil/springstatemachineexporter/ast/in/AstFileFinder.java
index 0616184..5a83136 100644
--- a/src/main/java/click/kamil/springstatemachineexporter/ast/in/AstFileFinder.java
+++ b/src/main/java/click/kamil/springstatemachineexporter/ast/in/AstFileFinder.java
@@ -6,17 +6,17 @@ import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 public class AstFileFinder {
-    private final CompilationUnit cu;
+    private final ASTParser parser;
 
-    public AstFileFinder(String source) {
-        ASTParser parser = ASTParser.newParser(AST.getJLSLatest());
+    public AstFileFinder() {
+        this.parser = ASTParser.newParser(AST.getJLSLatest());
         parser.setKind(ASTParser.K_COMPILATION_UNIT);
         parser.setResolveBindings(false);
-        parser.setSource(source.toCharArray());
-        this.cu = (CompilationUnit) parser.createAST(null);
     }
 
     public boolean hasClassWithAnnotation(String source, List<String> annotationNames) {
+        parser.setSource(source.toCharArray());
+        CompilationUnit cu = (CompilationUnit) parser.createAST(null);
         AtomicBoolean found = new AtomicBoolean(false);
         cu.accept(new ASTVisitor() {
             @Override
diff --git a/src/test/java/click/kamil/springstatemachineexporter/ast/in/AstFileFinderTest.java b/src/test/java/click/kamil/springstatemachineexporter/ast/in/AstFileFinderTest.java
index 7a83747..d6fa820 100644
--- a/src/test/java/click/kamil/springstatemachineexporter/ast/in/AstFileFinderTest.java
+++ b/src/test/java/click/kamil/springstatemachineexporter/ast/in/AstFileFinderTest.java
@@ -96,7 +96,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnTrue_whenClassHasMatchingAnnotation() {
-        AstFileFinder finder = new AstFileFinder(CLASS_WITH_ANNOTATION);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Service");
 
         boolean result = finder.hasClassWithAnnotation(CLASS_WITH_ANNOTATION, annotationNames);
@@ -106,7 +106,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnTrue_whenClassHasMultipleMatchingAnnotations() {
-        AstFileFinder finder = new AstFileFinder(CLASS_WITH_MULTIPLE_ANNOTATIONS);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Service", "Component");
 
         boolean result = finder.hasClassWithAnnotation(CLASS_WITH_MULTIPLE_ANNOTATIONS, annotationNames);
@@ -116,7 +116,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnFalse_whenClassHasNoAnnotation() {
-        AstFileFinder finder = new AstFileFinder(CLASS_WITHOUT_ANNOTATION);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Service");
 
         boolean result = finder.hasClassWithAnnotation(CLASS_WITHOUT_ANNOTATION, annotationNames);
@@ -126,7 +126,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnFalse_whenClassHasDifferentAnnotation() {
-        AstFileFinder finder = new AstFileFinder(CLASS_WITH_DIFFERENT_ANNOTATION);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Service");
 
         boolean result = finder.hasClassWithAnnotation(CLASS_WITH_DIFFERENT_ANNOTATION, annotationNames);
@@ -136,7 +136,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnTrue_whenClassHasFullyQualifiedAnnotation() {
-        AstFileFinder finder = new AstFileFinder(CLASS_WITH_FULLY_QUALIFIED_ANNOTATION);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("org.springframework.stereotype.Service");
 
         boolean result = finder.hasClassWithAnnotation(CLASS_WITH_FULLY_QUALIFIED_ANNOTATION, annotationNames);
@@ -146,7 +146,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnTrue_whenMultipleClassesAndOneHasAnnotation() {
-        AstFileFinder finder = new AstFileFinder(MULTIPLE_CLASSES);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Service");
 
         boolean result = finder.hasClassWithAnnotation(MULTIPLE_CLASSES, annotationNames);
@@ -156,7 +156,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnFalse_whenInterfaceHasAnnotation() {
-        AstFileFinder finder = new AstFileFinder(INTERFACE_WITH_ANNOTATION);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("FunctionalInterface");
 
         boolean result = finder.hasClassWithAnnotation(INTERFACE_WITH_ANNOTATION, annotationNames);
@@ -166,7 +166,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnFalse_whenEmptyAnnotationList() {
-        AstFileFinder finder = new AstFileFinder(CLASS_WITH_ANNOTATION);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = Collections.emptyList();
 
         boolean result = finder.hasClassWithAnnotation(CLASS_WITH_ANNOTATION, annotationNames);
@@ -176,7 +176,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnFalse_whenEmptySource() {
-        AstFileFinder finder = new AstFileFinder(EMPTY_SOURCE);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Service");
 
         boolean result = finder.hasClassWithAnnotation(EMPTY_SOURCE, annotationNames);
@@ -186,7 +186,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldThrowException_whenNullAnnotationList() {
-        AstFileFinder finder = new AstFileFinder(CLASS_WITH_ANNOTATION);
+        AstFileFinder finder = new AstFileFinder();
 
         // when & then
         assertThatThrownBy(() ->
@@ -196,7 +196,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnTrue_whenClassHasAnnotationAndFields() {
-        AstFileFinder finder = new AstFileFinder(CLASS_WITH_ANNOTATION_AND_FIELDS);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Service");
 
         boolean result = finder.hasClassWithAnnotation(CLASS_WITH_ANNOTATION_AND_FIELDS, annotationNames);
@@ -206,7 +206,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldHandleInvalidJavaSyntax() {
-        AstFileFinder finder = new AstFileFinder(INVALID_JAVA_SYNTAX);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Service");
 
         boolean result = finder.hasClassWithAnnotation(INVALID_JAVA_SYNTAX, annotationNames);
@@ -218,7 +218,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnTrue_whenAnnotationNameMatchesCaseInsensitive() {
-        AstFileFinder finder = new AstFileFinder(CLASS_WITH_ANNOTATION);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("service"); // lowercase
 
         boolean result = finder.hasClassWithAnnotation(CLASS_WITH_ANNOTATION, annotationNames);
@@ -228,7 +228,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnTrue_whenMultipleAnnotationNamesProvided() {
-        AstFileFinder finder = new AstFileFinder(CLASS_WITH_ANNOTATION);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Component", "Service", "Repository");
 
         boolean result = finder.hasClassWithAnnotation(CLASS_WITH_ANNOTATION, annotationNames);
@@ -238,7 +238,7 @@ class AstFileFinderTest {
 
     @Test
     void shouldReturnFalse_whenNoMatchingAnnotationNames() {
-        AstFileFinder finder = new AstFileFinder(CLASS_WITH_ANNOTATION);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Component", "Repository", "Controller");
 
         boolean result = finder.hasClassWithAnnotation(CLASS_WITH_ANNOTATION, annotationNames);
@@ -253,7 +253,7 @@ class AstFileFinderTest {
                 /* Another comment */
                 /** JavaDoc comment */
                 """;
-        AstFileFinder finder = new AstFileFinder(sourceWithComments);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Service");
 
         boolean result = finder.hasClassWithAnnotation(sourceWithComments, annotationNames);
@@ -264,7 +264,7 @@ class AstFileFinderTest {
     @Test
     void shouldReturnFalse_whenSourceContainsOnlyPackageDeclaration() {
         String sourceWithPackage = "package com.example;";
-        AstFileFinder finder = new AstFileFinder(sourceWithPackage);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Service");
 
         boolean result = finder.hasClassWithAnnotation(sourceWithPackage, annotationNames);
@@ -282,7 +282,7 @@ class AstFileFinderTest {
                     }
                 }
                 """;
-        AstFileFinder finder = new AstFileFinder(classWithAnnotatedParams);
+        AstFileFinder finder = new AstFileFinder();
         List<String> annotationNames = List.of("Service");
 
         boolean result = finder.hasClassWithAnnotation(classWithAnnotatedParams, annotationNames);