diff --git a/libs/services/src/os/DropBoxManager.cpp b/libs/services/src/os/DropBoxManager.cpp
index e8e34d7c4cb3a..95246a0d270f5 100644
--- a/libs/services/src/os/DropBoxManager.cpp
+++ b/libs/services/src/os/DropBoxManager.cpp
@@ -185,6 +185,11 @@ DropBoxManager::addFile(const String16& tag, const string& filename, int flags)
 Status
 DropBoxManager::addFile(const String16& tag, int fd, int flags)
 {
+    if (fd == -1) {
+        string message("invalid fd (-1) passed to to addFile");
+        ALOGW("DropboxManager: %s", message.c_str());
+        return Status::fromExceptionCode(Status::EX_ILLEGAL_STATE, message.c_str());
+    }
     Entry entry(tag, flags, fd);
     return add(entry);
 }
@@ -201,4 +206,3 @@ DropBoxManager::add(const Entry& entry)
 }
 
 }} // namespace android::os
-