diff --git a/app/src/main/java/com/nextcloud/client/jobs/upload/FileUploadHelper.kt b/app/src/main/java/com/nextcloud/client/jobs/upload/FileUploadHelper.kt
index c97fe56641..05d9bd1d55 100644
--- a/app/src/main/java/com/nextcloud/client/jobs/upload/FileUploadHelper.kt
+++ b/app/src/main/java/com/nextcloud/client/jobs/upload/FileUploadHelper.kt
@@ -64,6 +64,9 @@ class FileUploadHelper {
     companion object {
         private val TAG = FileUploadWorker::class.java.simpleName
 
+        @Suppress("MagicNumber")
+        const val MAX_FILE_COUNT = 500
+
         val mBoundListeners = HashMap<String, OnDatatransferProgressListener>()
 
         private var instance: FileUploadHelper? = null
diff --git a/app/src/main/java/com/owncloud/android/ui/activity/ReceiveExternalFilesActivity.java b/app/src/main/java/com/owncloud/android/ui/activity/ReceiveExternalFilesActivity.java
index aab5490acf..60d8c944a7 100755
--- a/app/src/main/java/com/owncloud/android/ui/activity/ReceiveExternalFilesActivity.java
+++ b/app/src/main/java/com/owncloud/android/ui/activity/ReceiveExternalFilesActivity.java
@@ -880,7 +880,7 @@ public class ReceiveExternalFilesActivity extends FileActivity
     }
 
     private boolean somethingToUpload() {
-        return (mStreamsToUpload != null && mStreamsToUpload.size() > 0 && mStreamsToUpload.get(0) != null ||
+        return (mStreamsToUpload != null && !mStreamsToUpload.isEmpty() && mStreamsToUpload.get(0) != null ||
             mUploadFromTmpFile);
     }
 
@@ -904,6 +904,11 @@ public class ReceiveExternalFilesActivity extends FileActivity
             return;
         }
 
+        if (mStreamsToUpload.size() > FileUploadHelper.MAX_FILE_COUNT) {
+            DisplayUtils.showSnackMessage(this, R.string.max_file_count_warning_message);
+            return;
+        }
+
         UriUploader uploader = new UriUploader(
             this,
             mStreamsToUpload,
diff --git a/app/src/main/java/com/owncloud/android/ui/activity/UploadFilesActivity.java b/app/src/main/java/com/owncloud/android/ui/activity/UploadFilesActivity.java
index da59551317..3bbdfe7752 100644
--- a/app/src/main/java/com/owncloud/android/ui/activity/UploadFilesActivity.java
+++ b/app/src/main/java/com/owncloud/android/ui/activity/UploadFilesActivity.java
@@ -30,6 +30,7 @@ import android.widget.TextView;
 
 import com.nextcloud.client.account.User;
 import com.nextcloud.client.di.Injectable;
+import com.nextcloud.client.jobs.upload.FileUploadHelper;
 import com.nextcloud.client.jobs.upload.FileUploadWorker;
 import com.nextcloud.client.preferences.AppPreferences;
 import com.nextcloud.utils.extensions.ActivityExtensionsKt;
@@ -653,6 +654,11 @@ public class UploadFilesActivity extends DrawerActivity implements LocalFileList
     @Override
     public void onConfirmation(String callerTag) {
         Log_OC.d(TAG, "Positive button in dialog was clicked; dialog tag is " + callerTag);
+        if (mFileListFragment.getCheckedFilePaths().length > FileUploadHelper.MAX_FILE_COUNT) {
+            DisplayUtils.showSnackMessage(this, R.string.max_file_count_warning_message);
+            return;
+        }
+
         if (QUERY_TO_MOVE_DIALOG_TAG.equals(callerTag)) {
             // return the list of selected files to the caller activity (success),
             // signaling that they should be moved to the ownCloud folder, instead of copied
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 765d842628..3c3df08a91 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -129,6 +129,7 @@
     <string name="uploader_error_message_source_file_not_found">File selected for upload not found. Please check whether the file exists.</string>
     <string name="uploader_error_message_source_file_not_copied">Could not copy file to a temporary folder. Try to resend it.</string>
     <string name="uploader_upload_files_behaviour">Upload option:</string>
+    <string name="max_file_count_warning_message">You have reached the maximum file upload limit. Please upload fewer than 500 files at a time.</string>
     <string name="uploader_upload_files_behaviour_move_to_nextcloud_folder">Move file to %1$s folder</string>
     <string name="uploader_upload_files_behaviour_only_upload">Keep file in source folder</string>
     <string name="uploader_upload_files_behaviour_upload_and_delete_from_source">Delete file from source folder</string>