diff --git a/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabase.java b/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabase.java
index b44f9af3c3bc7..8a3ebefa127ff 100644
--- a/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabase.java
+++ b/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDatabase.java
@@ -577,9 +577,7 @@ class MtpDatabase {
     static void getObjectDocumentValues(
             ContentValues values, int deviceId, String parentId, MtpObjectInfo info) {
         values.clear();
-        final String mimeType = info.getFormat() == MtpConstants.FORMAT_ASSOCIATION ?
-                DocumentsContract.Document.MIME_TYPE_DIR :
-                MediaFile.getMimeTypeForFormatCode(info.getFormat());
+        final String mimeType = getMimeType(info);
         int flag = 0;
         if (info.getProtectionStatus() == 0) {
             flag |= Document.FLAG_SUPPORTS_DELETE |
@@ -608,6 +606,17 @@ class MtpDatabase {
         values.put(Document.COLUMN_SIZE, info.getCompressedSize());
     }
 
+    private static String getMimeType(MtpObjectInfo info) {
+        if (info.getFormat() == MtpConstants.FORMAT_ASSOCIATION) {
+            return DocumentsContract.Document.MIME_TYPE_DIR;
+        }
+        final String formatCodeMimeType = MediaFile.getMimeTypeForFormatCode(info.getFormat());
+        if (formatCodeMimeType != null) {
+            return formatCodeMimeType;
+        }
+        return MediaFile.getMimeTypeForFile(info.getName());
+    }
+
     static String[] strings(Object... args) {
         final String[] results = new String[args.length];
         for (int i = 0; i < args.length; i++) {
diff --git a/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDocumentsProvider.java b/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDocumentsProvider.java
index 70a1aae86b959..033845401b4b2 100644
--- a/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDocumentsProvider.java
+++ b/packages/MtpDocumentsProvider/src/com/android/mtp/MtpDocumentsProvider.java
@@ -184,6 +184,9 @@ public class MtpDocumentsProvider extends DocumentsProvider {
     public ParcelFileDescriptor openDocument(
             String documentId, String mode, CancellationSignal signal)
                     throws FileNotFoundException {
+        if (DEBUG) {
+            Log.d(TAG, "openDocument: " + documentId);
+        }
         final Identifier identifier = mDatabase.createIdentifier(documentId);
         try {
             openDevice(identifier.mDeviceId);
@@ -270,6 +273,9 @@ public class MtpDocumentsProvider extends DocumentsProvider {
     @Override
     public String createDocument(String parentDocumentId, String mimeType, String displayName)
             throws FileNotFoundException {
+        if (DEBUG) {
+            Log.d(TAG, "createDocument: " + displayName);
+        }
         try {
             final Identifier parentId = mDatabase.createIdentifier(parentDocumentId);
             openDevice(parentId.mDeviceId);