diff --git a/uncrypt/uncrypt.cpp b/uncrypt/uncrypt.cpp
index cf068ba..d1970e5 100644
--- a/uncrypt/uncrypt.cpp
+++ b/uncrypt/uncrypt.cpp
@@ -300,7 +300,7 @@
     int head_block = 0;
     int head = 0, tail = 0;
 
-    android::base::unique_fd fd(open(path, O_RDONLY));
+    android::base::unique_fd fd(open(path, O_RDWR));
     if (fd == -1) {
         PLOG(ERROR) << "failed to open " << path << " for reading";
         return kUncryptFileOpenError;