diff --git a/src/main/java/org/apache/maven/plugins/checkstyle/exec/DefaultCheckstyleExecutor.java b/src/main/java/org/apache/maven/plugins/checkstyle/exec/DefaultCheckstyleExecutor.java
index bd306688..dee7ef93 100644
--- a/src/main/java/org/apache/maven/plugins/checkstyle/exec/DefaultCheckstyleExecutor.java
+++ b/src/main/java/org/apache/maven/plugins/checkstyle/exec/DefaultCheckstyleExecutor.java
@@ -436,21 +436,6 @@ private Properties getOverridingProperties(CheckstyleExecutorRequest request) th
     }
 
     private List<File> getFilesToProcess(CheckstyleExecutorRequest request) throws IOException {
-        StringBuilder excludesStr = new StringBuilder();
-
-        if (StringUtils.isNotEmpty(request.getExcludes())) {
-            excludesStr.append(request.getExcludes());
-        }
-
-        String[] defaultExcludes = FileUtils.getDefaultExcludes();
-        for (String defaultExclude : defaultExcludes) {
-            if (excludesStr.length() > 0) {
-                excludesStr.append(",");
-            }
-
-            excludesStr.append(defaultExclude);
-        }
-
         Set<File> files = new LinkedHashSet<>();
         if (request.isAggregate()) {
             for (MavenProject project : request.getReactorProjects()) {
@@ -501,11 +486,19 @@ private void addFilesToProcess(
             Collection<File> files,
             Collection<File> testSourceDirectories)
             throws IOException {
+
+        String excludes = request.getExcludes();
+        String defaultExcludes = String.join(",", FileUtils.getDefaultExcludes());
+        if (excludes == null || excludes.isEmpty()) {
+            excludes = defaultExcludes;
+        } else {
+            excludes = excludes + "," + defaultExcludes;
+        }
+
         if (sourceDirectories != null) {
             for (File sourceDirectory : sourceDirectories) {
                 if (sourceDirectory.isDirectory()) {
-                    final List<File> sourceFiles =
-                            FileUtils.getFiles(sourceDirectory, request.getIncludes(), request.getExcludes());
+                    final List<File> sourceFiles = FileUtils.getFiles(sourceDirectory, request.getIncludes(), excludes);
                     files.addAll(sourceFiles);
                     logger.debug("Added " + sourceFiles.size() + " source files found in '"
                             + sourceDirectory.getAbsolutePath() + "'.");
@@ -517,7 +510,7 @@ private void addFilesToProcess(
             for (File testSourceDirectory : testSourceDirectories) {
                 if (testSourceDirectory.isDirectory()) {
                     final List<File> testSourceFiles =
-                            FileUtils.getFiles(testSourceDirectory, request.getIncludes(), request.getExcludes());
+                            FileUtils.getFiles(testSourceDirectory, request.getIncludes(), excludes);
 
                     files.addAll(testSourceFiles);
                     logger.debug("Added " + testSourceFiles.size() + " test source files found in '"