diff --git a/src/main/java/org/apache/commons/fileupload2/FileUploadBase.java b/src/main/java/org/apache/commons/fileupload2/FileUploadBase.java
index 53682a9eb8..8f5200c54f 100644
--- a/src/main/java/org/apache/commons/fileupload2/FileUploadBase.java
+++ b/src/main/java/org/apache/commons/fileupload2/FileUploadBase.java
@@ -389,12 +389,7 @@ public Map<String, List<FileItem>> parseParameterMap(final RequestContext ctx)
 
         for (final FileItem fileItem : items) {
             final String fieldName = fileItem.getFieldName();
-            List<FileItem> mappedItems = itemsMap.get(fieldName);
-
-            if (mappedItems == null) {
-                mappedItems = new ArrayList<>();
-                itemsMap.put(fieldName, mappedItems);
-            }
+            List<FileItem> mappedItems = itemsMap.computeIfAbsent(fieldName, k -> new ArrayList<>());
 
             mappedItems.add(fileItem);
         }
diff --git a/src/main/java/org/apache/commons/fileupload2/util/FileItemHeadersImpl.java b/src/main/java/org/apache/commons/fileupload2/util/FileItemHeadersImpl.java
index 06fdf60afa..2c237a7d98 100644
--- a/src/main/java/org/apache/commons/fileupload2/util/FileItemHeadersImpl.java
+++ b/src/main/java/org/apache/commons/fileupload2/util/FileItemHeadersImpl.java
@@ -87,11 +87,7 @@ public Iterator<String> getHeaders(final String name) {
      */
     public synchronized void addHeader(final String name, final String value) {
         final String nameLower = name.toLowerCase(Locale.ENGLISH);
-        List<String> headerValueList = headerNameToValueListMap.get(nameLower);
-        if (null == headerValueList) {
-            headerValueList = new ArrayList<>();
-            headerNameToValueListMap.put(nameLower, headerValueList);
-        }
+        List<String> headerValueList = headerNameToValueListMap.computeIfAbsent(nameLower, k -> new ArrayList<>());
         headerValueList.add(value);
     }