diff --git a/jetty-core/jetty-http/src/main/java/org/eclipse/jetty/http/MultiPartFormData.java b/jetty-core/jetty-http/src/main/java/org/eclipse/jetty/http/MultiPartFormData.java
index 1f58648e6993..8e8b15122f11 100644
--- a/jetty-core/jetty-http/src/main/java/org/eclipse/jetty/http/MultiPartFormData.java
+++ b/jetty-core/jetty-http/src/main/java/org/eclipse/jetty/http/MultiPartFormData.java
@@ -317,6 +317,21 @@ public void setFilesDirectory(Path filesDirectory)
             this.filesDirectory = filesDirectory;
         }
 
+        private Path findFilesDirectory()
+        {
+            Path dir = getFilesDirectory();
+            if (dir != null)
+                return dir;
+            String jettyBase = System.getProperty("jetty.base");
+            if (jettyBase != null)
+            {
+                dir = Path.of(jettyBase).resolve("work");
+                if (Files.exists(dir))
+                    return dir;
+            }
+            throw new IllegalArgumentException("No files directory configured");
+        }
+
         /**
          * @return the maximum file size in bytes, or -1 for unlimited file size
          */
@@ -627,7 +642,7 @@ private void createFileChannel()
             {
                 try (AutoLock ignored = lock.lock())
                 {
-                    Path directory = getFilesDirectory();
+                    Path directory = findFilesDirectory();
                     Files.createDirectories(directory);
                     String fileName = "MultiPart";
                     filePath = Files.createTempFile(directory, fileName, "");
diff --git a/jetty-core/jetty-http/src/test/java/org/eclipse/jetty/http/MultiPartFormDataTest.java b/jetty-core/jetty-http/src/test/java/org/eclipse/jetty/http/MultiPartFormDataTest.java
index c96c2035b654..efe48ff6de0d 100644
--- a/jetty-core/jetty-http/src/test/java/org/eclipse/jetty/http/MultiPartFormDataTest.java
+++ b/jetty-core/jetty-http/src/test/java/org/eclipse/jetty/http/MultiPartFormDataTest.java
@@ -912,6 +912,28 @@ public void testTerminalFailureIsTerminal()
         assertThat(chunk.getFailure(), instanceOf(NumberFormatException.class));
     }
 
+    @Test
+    public void testMissingFilesDirectory()
+    {
+        AsyncContent source = new TestContent();
+        MultiPartFormData.Parser formData = new MultiPartFormData.Parser("AaB03x");
+        // Always save to disk.
+        formData.setMaxMemoryFileSize(0);
+
+        String body = """
+            --AaB03x\r
+            Content-Disposition: form-data; name="file1"; filename="file.txt"\r
+            Content-Type: text/plain\r
+            \r
+            ABCDEFGHIJKLMNOPQRSTUVWXYZ\r
+            --AaB03x--\r
+            """;
+        Content.Sink.write(source, true, body, Callback.NOOP);
+
+        Throwable cause = assertThrows(ExecutionException.class, () -> formData.parse(source).get(5, TimeUnit.SECONDS)).getCause();
+        assertInstanceOf(IllegalArgumentException.class, cause);
+    }
+
     private class TestContent extends AsyncContent
     {
         @Override